with a 'shore dive' looking at plants and animals photographed in their natural habitat. Then deep down vertical underwater cliffs
at St. Kilda to have a look at beautiful animals with gruesome or unusual names
like Dead Mans Fingers or Lumpsucker. On the way back to the surface we meet the Basking
Shark, the second largest fish in the world,(10m) looking
into the gaping mouth to see its gill rakes.
Below is the presentation
Marine World in verbatim with pictures to illustrate the text.
Copyright © Tony Crabtree
and the Space Pictures below courtesy of NASA
NASA Visible Earthhaddenum
The Marine World
The surface of our planet is approximately
71% water and contains five oceans, including the Arctic, Atlantic, Indian,
Pacific and Southern but today we are going to concentrate on diving around
the British Isles. The water around England, Scotland, Wales and Ireland is
quite spectacular, some of the best temperate water diving in the world is
right here at home - the British Isles. The reason it is so
spectacular is because this sea water doesn't just sit static around the
British Isles, it is changing and moving all the time because the world is
spinning, this circulates the sea water. This moving water is being
supplied from the North Atlantic which is circulating clockwise between
Africa, the Caribbean Gulf and it is joined with water from the
Mediterranean and the Polar Seas. All this circular movement of the
Atlantic water is the result of the world spinning on its axis. The
water in the Gulf of the Caribbean has the tropical sun shining on it all
the year round. The water gets very warm and this hot Caribbean Gulf
water is then drawn into the Atlantic Ocean and joins the clockwise
circulation of the North Atlantic.
Caribbean, the British Isles, the North Atlantic,
Mediterranean, N/W Africa and the Straits of
The arrows illustrate the flow directions in the North Atlantic and the worlds oceans.
The Gulfstream water flowing north easterly along America.
This hot Caribbean Gulf water floats on top of the cooler Atlantic water -
it is called the Gulf-stream. The Gulf-stream water flows north-easterly along
the east coast of America and turns east travelling all the way across the
Atlantic to the British Isles, it then circulates into the English Channel,
the Irish sea, the west coast of Ireland and the west coast of Scotland,
over the northern top of Scotland and down into the North Sea. Because
of the world spinning on its axis this also circulates sea water from under
the polar ice to join the Atlantic water circulation.
Sea water joins the Atlantic circulation at
north-east corner of Africa at the Straits of Gibraltar.
The Mediterranean water is also heated by the sun but because the
Mediterranean water is quickly evaporated it has become much
saltier, this makes sea water from the Mediterranean denser than the
Atlantic water. Although it is warm this Mediterranean water sinks and
forms a counter-flow which goes north along the west coast of Portugal
and French coasts and joins the British Isles water. So we have
animals living here in the British Isles that came from the Caribbean &
North East corner
of Africa at the Straits of Gibraltar. Mediterranean water sinks and forms a
counter-flow which goes north along the west coast of Portugal and French
coasts and joins the British Isles water.
All this Spring reproductive activity causes a plankton
bloom in the
waters around the
British Isles which can be seen particularly
at the Western approaches - the bottom left-hand
side of the picture.
We also have animals from the polar regions of the North Atlantic. There are
fish that live under the polar ice all of their lives and, to stop themselves
from freezing, they actually have antifreeze in their bodies'. Some of them move to Englandís shallow coastal waters.
come especially to lay their eggs in our waters because it warms up quickly in
the spring. I will show you later one of the fish that does this but
there are lots of other fish and animals of various kinds e.g. crabs,
lobsters, crayfish who use these shallow waters as a nursery in the Spring to
All this reproductive spring activity causes a plankton bloom in the sea - it
is a mixture of plant and animal reproduction.
This picture shows the Western Atlantic Ocean
with colour to illustrate the different depths of the water.
If we look at the coastal waters around
the British Isles, you will find that the average depth is very shallow.
This picture on the left shows the Western Atlantic Ocean with colour
co-ordination to illustrate the different depths of the water of the
Western Atlantic. The light green colour is where the edge of the continental
shelf lies around the British Isles, the dark blue colour is showing where sea
is deeper. Shallow seas
cover all the continental shelves. These waters are where the oceans are
most productive, where biomass is highest and where all the major sea
fisheries of the world take their catches. The shallow seas include warm
tropical waters, temperate seas like those around the UK and the chilly
waters of the Arctic and Southern Oceans.
The picture on the right shows St Abbs harbour and the
surrounding coast looking south from the coastal path that leads up to the
St Abbs light house.
If you go on any coastal paths never
leave that path - there are dangers which are "sneaky" and you will not know
the dangers are there until it is too late. On the left-hand side of the picture(
on the right )
you can see some vertical cliffs - when we go underwater we will swim around
vertical cliffs underwater - in the same way as birds can fly around the cliffs in
this picture. Letís go on our first dive starting at St. Abbs on the east
coast of the British Isles just north of the Scottish
border and in the North Sea.
St Abbs Harbour
and the coast looking south from the coastal path that leads up to the St
east coast of Scotland.
St Abbs Harbour at high water.
Having arrived in the local car park you have a choice of hiring a dive boat
and going on a boat dive but, on this first dive, we have chosen a shore
dive from the outer harbour wall. As you walk around the harbour wall
you will notice that sometimes the harbour is full of water (at high tide)
and sometimes the harbour is empty (at low tide). It takes 6 hours and
20 minutes for the sea to rise to high tide, then 6 hours and 20 minutes for
the tide to fall to low water. The first picture of St Abbs harbour was
taken at high tide.
The second picture was
taken at low tide.
The children in the picture are collecting shells some of the shells are
very pretty. The children are quite safe providing they donít walk on the
rocks that are covered in seaweed. Walking on seaweed anywhere can
be dangerous because it has very shiny surfaces which protect it from damage.
These shiny surfaces are very slippery when you stand on them so please never
try to walk on seaweed.
Continuing around the outer harbour we approach
the water on the seaward side of the harbour wall to a place called Sheepís
St Abbs Harbour at low water.
this water movement is caused by a combination of the Moon in orbit around the
Earth and the Earth and Moon in orbit around the Sun.
The Moon in
in orbit around
The Moon in
in orbit around
a very popular safe entrance offering easy access at any state of the tide.
It has a gentle slope which is covered in barnacles and seaweed but, please
remember, donít walk on the seaweed, sit down, fit your fins to your feet,
make sure the air tanks are switched on, set the compass, and make sure that
your mask is water tight. This is a very exciting time for a novice diver
especially if this is your first sea water dive in the British Isles. You
are going to see things that you have never seen before.
On entering the water the diver will see for the first time the green sea,
this greenness is made by millions of bits of life floating in the water -
it is called plankton.
Divers getting ready to enter the water at the outer harbour.
Location Sheep's Hole, St Abbs
Diver swimming over
a Kelp Forest containing the many different seaweeds we will find around the
Sheepís Hole - St. Abbs, Scotland.
Plankton is made up of animal larvae and plant
spores. It is the beginning of the underwater food chain - you will see
examples of this later. The divers adjust their buoyancy so that they float
just below the surface. This is their first underwater view at Sheepís
Hole. The rocks there are covered in a kelp forest which is made up
of different kinds of seaweeds
- we will find them all around the British Isles. With names like
Bladder Rack, Saw Rack and the edible Sea Lettuce. The kelp plant is one of
the bigger varieties and grows very quickly, if it was to start from first
attachment in March it could be fully grown by June.
All these different seaweeds grow anywhere
where there is enough light for them to grow. The seaweed photosynthesise
the sunlight this makes them grow and in this process seaweeds gives off
oxygen into the water, 50% of all oxygen is made by plants in the sea. This means that half the oxygen that you are
breathing was made by the plants in the sea. Let's go and explore the kelp
forest. If we look at one kelp plant - starting at the top there is the
frond, this is the equivalent of leaves on a tree. The frond is the place
where the kelp makes oxygen by photosynthesis.
One individual kelp plant using the power the of sun to photosynthesise
and in this process seaweeds give off oxygen into the sea water.
Hole at St Abbs, Scotland.
There are animals we will find later that will
keep the kelp frond clean - a bit like a window cleaner. Some are
extremely pretty. The next
part of the kelp plant is called a stipe, it is the equivalent of a tree's main
trunk. All the parts we have looked at up to now are very strong and very bendy like
a leather strap. The kelp plant has to attach itself to the seabed. It can
only do this on something that is solid and strong. The kelp will grow on
rocks, shipwrecks, man-made structures like floating buoys, mooring chains
or piers. The kelp grows from a spore floating in the plankton and when it
lands on something that is solid it will stick itself down with some of its
own "superglue" .
Once it is attached it will start to grow its holdfast very quickly. As
plant gets bigger it grows new growth over the younger parts of the holdfast
and it will continue to grow bigger and stronger. After it has grown over itself several times
it leaves spaces that are safe places for young animals to start life in, this could be
a baby lobster, baby crab, fish eggs, fish fry, juvenile sponges, starfish,
sea urchins, any new animal that needs a safe home. The kelp forest itself, when fully grown, becomes
a safe habitat for other animals to start life or live in. The kelp plants are extremely
tough - they have to be - the sea can be very violent and stormy.
Kelp holdfast growing on to solid rock with a variety
animals, Starfish, Hermit crab, Soft corals, Sponges.
Location - St Abbs Head, by St Abbs Lighthouse.
If kelp gets
damaged it will re-grow either a new frond, a new stipe or, if only the holdfast
is left, it will grow a new plant. If you look around the holdfast you will see
other animals living there, the hermit crab, soft corals, sponges, sea
urchins, tube worms and clams. All these animals feed in different ways so
that they are not in competition with one another e.g. the clam gets its
food from pumping the plankton in the seawater through itself to filter
the water to get food; the sponges (of several colours) they also filter the
sea water. The hermit crab is looking around for food and finds bits with
his claws and puts them in his mouth to eat. The hermit crab doesnít have a
shell of his own and he has a soft body so when he leaves the holdfast he
has to find an empty shell that somebody else has made. They usually use
empty snail shells where the snail has either died or has been eaten by another animal that
has left the shell behind. The hermit crab then will use the
shell he finds until heís too big to fit into his present "home". He is
always on the lookout for a bigger shell to move into. If you watch you can
give him an empty shell, put it next to him and he will, if you wait a few minutes, make sure that there is nobody living in the shell and,
if he thinks it fits him better he will transfer
into the new shell. This is an example of nature
recycling anything useful. Just next to the hermit crab is an example
of a soft
coral. Corals have to live in places' where the sea waves wash food over them
to eat. The starfish walks around on hundreds of tubular legs with
suckers on the end. If you remember, I said earlier there are fish that come
from coastal areas under the polar ice to our British Waters to
lay their eggs.
If you look carefully you will find them usually in places
where patches of the rock have been cleaned so that nothing is growing or
living on it. The fish that do this clear and clean the rock surfaces
with their teeth, then guard the area day and night and wait. Please
see if you can see the fish that is guarding this bare patch of rock.
Lumpsucker or Lumpfish Cyclopterus lumpus
is brilliantly camouflaged so that most divers just donít see him. I call
him Mr Happy you will see why in the next pictures. If you approach where Mr
Happy is hiding as you get near he will come up to you and swim round you.
If you look
carefully you will find where patches of the rock have being cleaned. All
the lump sucker pictures were taken on the east
coast of Scotland, outside the little harbour called Cove. north of St. Abbs Head.
The female has laid her eggs, The male Lump Sucker is in the picture
(camouflaged) guarding the 300,000 eggs.
Youíll see why I call him Mr. Happy - his mouth
has got a big wide "smile" - but this is not his real name,
his real name is Lump Sucker.
strange name describes what he actually was doing in the last picture when
you couldnít see him. Mr Lump Sucker has, underneath his chin, a sucker
which he uses to stick himself down to the sea bed. He uses the sucker to
stop himself from being washed and swished about by the waves above. This
saves energy when itís rough weather. When Mrs Lump Sucker arrives from her
long journey coming from cold
polar waters she will lay her eggs where dad has prepared, then he will
fertilise the eggs.
The Lump Sucker
(Mr Happy) is hiding. As you get near he will come
up to you and swim round you.
Mrs Lump Sucker is much bigger than dad she
is also different colour - very dark green. She doesn't need any camouflage.
When mum has laid her eggs she leaves dad in charge and moves away. Mr
lump Suckers job is to stay and guard the eggs that mum has just laid, day
and night. If the eggs were not protected and guarded by dad the 300,000
eggs that Mrs lump sucker laid would be eaten by all the other fish and
this picture on the right you'll see why I call him "Mr. Happy" - he has a big
wide happy smile, Sometimes Mr Happy the Lump Sucker, when swimming around
you, will try to lead you away from the eggs, if he does this you need to
set your compass so that you will know which way he is leading you because, after
a few yards, he will suddenly dive into the kelp and stick himself somewhere
to hide hoping you will leave the area then, after you have gone, he
will make his way back to the eggs and carry on guarding them.
Mr Lump Sucker - I call him Mr Happy because of his big "smile"
Mr Lump Sucker leading you away from the eggs.
you find him he will then stay with you and if you put your hand out
flat he will sit on it. You can then let your compass swing back
to where the eggs are. If you do this he will stay on your hand but he will
still make sure that nothing is eating the eggs. He will, in the end, come off your hand and,
after you have gone, let his sucker stick down next to the eggs. As
well as guarding the eggs 24 hours a day 7 days a week until they hatch
Mr Lump Sucker also has to circulate oxygenated water around the eggs by
fanning them with his tail.
Mr Lump Sucker hiding under the kelp using his sucker.
This picture shows the sucker underneath his body.
Mr Lump Sucker happily sitting on a diver's hand. He
will still keep his eye on the 300,000 eggs.
Please note to
protect his soft skin Mr Lump Sucker
has bony nodules on his body.
This is another reason why he needs his sucker, when Mr Lump Sucker is fanning the eggs with his
tail he uses his sucker under his chin like a handbrake,
like we do when parking a car, by sticking himself down with this sucker when he wags
his tail he forces the water over the eggs
and doesnít move himself forward. Mr Lump Sucker and Mum are unusual fish
they do not have scales and, to protect the soft skin, they have only bony
nodules along their body sides. Later, when the eggs
hatch, dad still will protect and guard the fish fry - you sometimes see them
sitting on dad using their suckers so that they can stay where ever he goes.
Mr Lump Sucker attaching himself back on to the seabed to
guard the eggs until the eggs hatch.
The Sea-Urchin will pick up any debris to camouflage itself.
Location - Wolf Rock four miles south west of
Lands End, Cornwall.
sometimes called the Sea Hedgehog. The sea-urchin is a spiny,
hard-globular shelled animal that lives on the rocky seafloor.
They also will
sometimes use camouflage to try and protect themselves. They canít change colour
so they pick up any loose things they find on the seabed and wrap it round
themselves e.g. bits of seaweed bits of plastic basically anything they find
to confuse predators. The spines are attached to the shell with universal
joints so that the spikes can move in any direction.
They are for defence. In
between all the spines there are tubular legs with suckers on the end of each leg.
You can see the diver (which happens to be me). I am using my finger to tickle
the spikes of the sea urchin this will make the sea-urchin pump water in
through its mouth to inflate tubular legs. This is how they pick up bits of
and debris to camouflage themselves from predators. When they have
inflated the tubular legs they can then use them to step across gaps in the rocks or travel on vertical
The Sea-Urchin has inflated it's tubular legs.
Location - St Abbs on the east coast of
the Sea-Urchin showing suckers on the end of their inflated legs.
Kilkee on the west coast
grazing the rocks and
encrusting pink Coralline Alga -
Lithophyllum incrustans. Location - Kilkee
on the west coast of Ireland.
They can even walk on overhanging surfaces. If
you look in between the spikes and the tubular legs youíll see that there
are shorter tiny three pronged structures called
pedicellarines they are small stinging structures that are used for defence
and for obtaining food. The sea-urchin will graze on anything on the
sea bed, plants or animals.
The Sea-Urchin (close) up
uses five self sharpening teeth. Location - Skellig Islands, west coast of
Sea-Urchin using this tubular legs step across the rocks
Location - Kilkee, west coast Ireland.
To eat the food they find, they have five self-sharpening teeth that are
sharp enough to cut rock off the seabed. They will
be able to
remove everything living on an area depending on how many there are in the
population. If they over-graze a particular area they will starve and die but
because the seawater around is full of sea-urchin larvae the area will be
regenerated. Sometimes this will take two or three years.
The seven-armed Starfish Luidia ciliaris (on the
is easily recognised by its fringing spines and long feet with which it
moves across the seabed relatively rapidly. It can exceed 40cms across and
is a fearsome predator on shellfish and other starfish.
starfish is trying to catch Brittle stars but they are trying to escape from
being eaten. The seven-armed Starfish
will sometimes be in the sand or gravel half buried waiting for prey. They
are very common on the south and west coasts and islands of the British
The Seven-armed Starfish Luidia ciliaris
Location - Bridges of Ross, Loop Head, Ireland.
Common Sun-star or Crossaster
The Sun-star can be
seen in many different colours. In the first picture the Sun-star
is trying to catch the
Brittle-stars and Feather-stars. It is using its tubular legs to move across the seabed to catch them and when it is successful the Sun-star will climb over
the Brittle-star or Feather-star. Sun-star will then extrude its stomach over them to eat
them, it will also find bits of dead fish, crabs, or climb over
snails and attack by extracting them out of their shell with its tubular legs.
This particular Sun-star starfish has thirteen stomachs one for each arm.
Sun-star trying to catch Brittle-stars & Feather-stars.
Location - Cathedral Rock, St Abbs east coast of Scotland.
The underside of the
Sun-star with its stomachs showing Location - Cathedral
Rock, St Abbs east coast of Scotland.
Common Starfish - Asterias rubens All
the starfish in this picture have got their five arms interlocked with their
neighbours to prevent any other animals from eating the dead body (the
fish that is under all these starfish). They will share the fish's body.
When the starfish at the bottom of this pile have had enough to eat they
will move to the top of the pile and the new starfish just arriving will make their way down to the bottom extrude their stomachs and start to
eat. All the many different kinds of starfish perform a very
important function in the sea because of their eating habits.
Common Starfish Asterias rubens feeding.
Location - St Abbs east coast of
Common Starfish Asterias rubens regenerating its fifth damaged arm.
Location - St Abbs east coast of Scotland.
They don't seem very fussy, they will eat anything they find dead or alive. We have in our world service providers like the dustbin
man, the road sweeper, the undertaker, caretakers and window cleaners.
Starfish have accidents, when this happens the starfish can regenerate any
part of their damaged body, if it was cut in half, each half will regenerate
the parts that needed replacing. If you remember when I first started talking
to you I showed you vertical sea cliffs I said that we would be going diving
around underwater sea cliffs floating around where ever you like to go.
cliffs in the picture to the right are covered by soft corals with a spooky,
name they are called Dead Man's Fingers Alcyonium digitatum. Dead
flourish all around the British Isles. They like to be where there is
moderate wave movement and they will also live happily in parts of the coast
where the flow is quite strong because of the tides. Dead Man's Fingers will
not tolerate any location where there is sand or fine sediment. You will
find Dead Man's Fingers in several different colours.
Diver on the underwater cliff.
Location - Longships Reef by Eddystone Lighthouse
Dead Man's Fingers their polyps extended to feed on the
plankton. Location - Manacles Reef, Cornwall.
The picture on the left shows my hand next
to white Dead Man's Fingers. In the same picture there are orange Dead
Man's Fingers. Some are bright red. They are all the same type
of animal. In the picture on the left the white Dead Man's Fingers (near to
my hand) are feeding using extended polyps to catch plankton
out of the water. If you were to touch this animal all the polyps will
deflate and pull back into the main body. They are still safe to touch. The
Dead Man's Fingers in the picture (on the right below) all the polyps have stopped
feeding and have retracted their polyps which makes them look similar to a
After storms at sea sometimes these
Dead man's Fingers are washed up on the beach - this is how they got the name
"Dead Man's Fingers". Dead Man's Fingers grow their body to be in harmony with
their surroundings. When in a stormy location they will grow a strong stumpy
body shape - as in the pictures. If they live in a location where there is
fast water movement and no wave action they grow into slim and delicate
My favourite of the Dead Man's Fingers we have in British waters is of a
red colour - if you don't dive with torch you will not realise how beautiful
Dead Man's Fingers with their polyps deflated.
Location - Manacles Reef, Cornwall.
Red Dead man's Finger colony Alcyonium glomeratum. they thrive
where the water is clean and fast-moving.
Location - Penzance Cornwall. (self-portrait).
Red Dead Man's Finger colony close-up with its polyps feeding.
Please note the individual bits of plankton on the polyps. Location -
The red Dead Man's Fingers in the picture above are Alcyonium glomeratum
these animals are only found in warmer waters - along the west coast of England,
the English Channel, along the west coast of Ireland, in the Irish sea at Bardsey Island,
Wales, on the west coast of
Scotland and at St Kilda. They can grow into huge colonies and
thrive where the water is clean and fast-moving. They also like coasts
that receive the Atlantic swell and surf. Pictured below are Red Dead Man's Fingers and one
of my favourite fish the Goldsinny Wrasse. He has to
investigate what is happening in his territory.
Red Dead Man's Finger colony with polyps deflating.
Location - Penzance, Cornwall.
Goldsinny Wrasse pictured with Red Dead Man's Fingers.
Location - Manacles Reef, Cornwall.
I call him "cheeky chops" (this is not his
real name) but it does describe his behaviour. "cheeky chops" - the
rupestris or Goldsinny Wrasse as it is sometimes known, is a very common
fish around the British Isles. They are very territorial and defend their
patch with vigour. When any diver enters into "cheeky chops" home ground he
will follow you around and interfere with any pictures you try to take. Some
of this strange behaviour is because you disturb food that he could eat.
You will see him chasing away any rival Goldsinny Wrasse. The picture below shows the Goldsinny Wrasse watching me while I take our picture.
This is typical behaviour they are in credibly inquisitive, quick to learn,
I have witnessed them cleaning other fish
because the Goldsinny Wrasse is a territorial fish
other fish have then observed their behaviour and taken advantage of this.
It has become known "in the fish world" that the Goldsinny Wrasse will
clean visiting fish, providing the visiting fish keep still and calm. The
attraction for the Goldsinny Wrasse is a regular food supply. "Cheeky chops"
will find his own varied diet which includes worms, small encrusting all animals
which he can easily tackle with his sharp forward pointing teeth
e.g. young crabs, shrimps. "Cheeky chops" will find these items of
food amongst the Plumose Anemones - Metridium senile
Cheeky chops will find their items of
food amongst the Plumose
Anemones-Metridium senile in pink and white. Location - The
Stags half a mile south of The Lizard which is the most southerly point of
Goldsinny Wrasse has used its sharp
teeth to cut out a place to hide or sleep.
Location- Skellig Islands West coast of Ireland.
The Goldsinny Wrasse is
a day-time feeding fish. They all need somewhere to sleep at night. Many of
the British Isles coasts have
underwater boulder slopes so plenty of places to get a safe night's sleep.
But there are places where the Goldsinny Wrasse has to make a "bedroom" inside
another animal's body. The picture on the left shows one in use Bryozoa Ross -
this colony has been used and modified by the resident - the Goldsinny Wrasse.
It has used its sharp teeth to cut out a place to hide in or sleep. It is very fragile
- like our potato crisps - and the fish can
easily cut their way in. Bryozoa Ross can be found in the warmer
waters of the British Isles, the English Channel, along the west coast of
England, in the Irish sea, along the west coast of Ireland, the west coast of Scotland.
and also in the Mediterranean.
The next fish we are going to look at is the Ballan Wrasse or
which can be found all around the British Isles among rocks
and kelp forests. This particular animal
is 40cms long and lives just outside some
rock caves at St Abbs called Cathedral Rock on the east coast of Scotland.
It is a very popular dive site and can be accessed from the outer harbour wall
at St Abbs. A short swim will take you to Cathedral Rock. The Ballan
expect you to bring food with you. They will be quite disappointed if you
don't feed them and will, in fact, get very impatient and butt you.
Ballan Wrasse - Labrus bergylta.
Also in the picture are Saithe,
- a shoaling fish.
Location - Cathedral Rock, St Abbs east coast of Scotland.
This is not dangerous - they are just impatient. They will
break the sea urchin shell themselves when you're not there. It is possible
to identify individual fish by their scars - this is because their pectoral
fins sometimes split. Some of the scars they receive are from attacks by
seals. If they escape this encounter, when you have repeat dives over a
period of years, you will recognise your old friend with his beautiful eyes
and damaged fin or scars. The Ballan Wrasse live in small groups. They are
slow-growing fish and are thought capable of
attaining 30 years of age.
Ballan Wrasse Labrus bergylta
watching you with his beautiful eyes.
Location - Cathedral Rock, St Abbs.
Ballan Wrasse Labrus bergylta
eating sea urchin
Location - Scapa Flow Block Ship: Goberanada Boris.
In this picture on the left I am offering the Sea Urchin -
echinodermata for the
Ballan Wrasse to eat. They won't eat the shell but they love the Sea
Urchin eggs that are inside. This is their normal food which they'll find
themselves when there are no divers at Cathedral Rock. The Ballan Wrasse with
its sharp teeth can easily tackle a varied diet which includes small
encrusting animals, young crabs, and shrimps but, because of divers'
behaviour, there are very few sea urchins in the area of Cathedral Rock.
In the picture on the right is the female Cuckoo Wrasse
she is pink with white and brown marks on the top of her tail.
She is feeding
on the eggs of a sea urchin which she has broken herself. Also in the picture
is someone you should recognise, yes, one of
my favourites "cheeky chops". He too is waiting for his chance to eat some of
eggs. You can see how concentrated life can be underwater - there are two
colour varieties of Dead Man's Fingers also you will notice the white Sand
eyed Anemones - Sagartia elegans they catch their food from the passing water.
Cuckoo Wrasse Labrus-mixtus
Location - Skellig Islands on the west coast of Ireland.
Female Cuckoo Wrasse starting to change colour into a male.
Location - Calf of Man, Isle of Man.
The fish in the picture on the left is a female Cuckoo Wrasse.
If you where to be a Cuckoo Wrasse, you would all be born female. Just imagine,
ladies living in a world with no males around. Some of the males in your territory in the sea will be eaten by the
seals. Some of them
get caught in fishing nets and some die of old age. However you do need males
to fertilise your eggs. To get round this problem of shortage of male Cuckoo
Wrasse some of you ladies will have to change into a male Cuckoo Wrasse !
When the female Cuckoo Wrasse starts to change into a male
she will begin to lose the white and brown marks on the top of her pink
tail. You can see in the picture above that the tail has gone blue
face is beginning to get blue stripes. In the picture on the right the female
has completely changed from female to male and has now become this beautiful
dazzling blue striped male. All this change of colour is to display to the
females that he is ready to fertilise any eggs the females wish to lay. When
the male has attracted a female to follow him he will lead her
to a place of his choice and allow her to lay her eggs.
This male Cuckoo Wrasse has completely changed colour and will behave
for rest of his life as a male. Location - Outer breakwater Port Erin, Isle
Male Cuckoo Wrasse asleep in its safe rocky night-time
resting place. The fish cannot close their eyes - they appear just to be in a
trance whilst they are asleep. Location Calf of Man, Isle of Man.
He will then fertilise eggs. The female will not have any further responsibility for the eggs. It
is the male Cuckoo Wrasse's job is to guard the
eggs day and night. If they need ventilation he will fan them to keep the
eggs oxygenated. The Wrasse family of fish all reproduce in this way and
they are daytime feeders. If you go diving at night you will find them in a safe
place having their sleep. When sleeping they cannot close their eyes -
they appear to be in a trance. On the bottom left of this picture
there are two crabs mating. When not mating crabs normally feed at
night. In the underwater world there is a day shift and a night shift.
St Kilda has tallest sea cliffs in the British Isles and because of its
location it has dramatic sea conditions waves 8 or 10 metres high.
With wind velocity of the 130miles an hour.
Come with me and I will show you around
the Islands at the "edge of the world". The
St Kilda Archipelapelago is a remote Atlantic group of Islands 64 km west of
the Outer Hebrides on the west coast of Scotland. 18,000 years ago the sea
was 120m shallower. St Kilda was one volcanic island. As the ice
melted at the end of the ice age the sea became deeper to its now present depth.
St Kilda now only consists of four main islands - Hita, Soay, Boreray and
Dun. Three sea stacs - Stac an Armin, Stac Lee and Levenish: and great number of
smaller stacs and skerries.
St Kilda is one of two dozen global locations
to be awarded World Heritage Status. It is a remote, wild, beautiful place.
There are spectacular sea cliffs (the tallest in the British Isles). St Kilda is
one of the best diving destinations in the whole of the British Isles
especially for its crystal clear 60 metre visibility and blue waters. Because of its
location St Kilda has dramatic sea conditions some waves 8 or 10 metres
high with wind velocity of 130 miles an hour. Consequently all this
erosion has left us with spectacular underwater cliffs, caves and trenches
Dramatic sea conditions waves 8 or 10 metres high sending sea spray over the
St Kilda is one of the best diving destinations the whole of
the British Isles, especially known for its crystal clear 60 m visibility.
Location - St Kilda.
St Kilda is the major
seabird breeding station in the North Atlantic. It has the largest colony of
Northern gannets nesting in the world on Boreray and Stac Lee.
Location - St Kilda at Stac Lee.
Diving these vertical walls is like flying, you are defying gravity by being
neutrally buoyant in the water. Location - St Kilda at Stac Lee.
In the picture above is Stac Lee it is 165
metres high and covered with nesting gannets. It is the biggest colony of gannets in the
Northern Hemisphere. The vertical cliffs around this sea stack carry on
underwater, These same vertical cliffs underwater are now covered in
Plumose Anemones with Crabs and Squat Lobsters
(with their spectacular colours) hiding in the cracks. In the picture on the
lef the diver
is using his torch to look into the many nooks and crannies
in the rocks to see who is living in them. Diving these vertical cliffs is
like flying, you are defying gravity by being neutrally buoyant in the
Diver using his torch to light up cracks just where the
Squat Lobster will typically hide for the day. The diver's torch will show
the true colours of the Squat Lobster.
Location - St Kilda at Stac Lee.
The Spiny Squat Lobster - Galathea strigose
with his body
camouflaged with fluorescent blue stripes - these beautiful colours red and
blue will confuse predators.
Location - St Kilda at Stac Lee.
The Spiny Red Squat Lobster
in the picture above on the right with his body camouflaged with fluorescent
blue stripes. These beautiful colours - red and blue - will confuse
predators who find their food in daylight. More importantly, the red
shell cannot be seen because the colour red will not transmit through green
sea water. This is why most divers carry an underwater torch so they
to can see true colours. In the (picture on the right) is my diving buddy and the rocks are covered with
one of my favourite animals Jewel anemones Corynactis viridis they are
known for their patches of spectacular varieties of
In the picture above my diving buddy with the
rocks covered with my favourite animal, Jewel anemones.
Location- Bardsey Island- Llyn Peninsular North Wales.
Green Jewel Anemones (life size) with purple
stinging tentacles and with their mouth in the centre to eat their prey.
Location - Blasket Islands,
west coast of Ireland.
When I first saw them on the Manacles
Reef in Cornwall
their beauty just "blew me away". I wondered why was there such beauty hidden
away under the sea where nobody could see them but, there is a reason, it is
a warning telling animals who might think to eat them to keep away. The
Jewel Anemones are deadly predators they are equipped with hundreds of stinging
tentacles. They generate their own lights on the end of each tentacle to
attract the plankton to swim to their glowing tentacle tips. They grow a
smooth column body up to15mm in height and diameter.
They come in every colour that you can imagine -
brilliant blue, green, red, pink, purple, orange, white, or brown and
various combinations of colours that can get mixed when they reproduce
sexually. They can also reproduce by longitudinal fission, i.e.. dividing
in half vertically by cloning themselves. This results in patches of
identical related Jewel Anemones as in the picture on the right - different colours
- some could be pink and male and the brown ones bottom left
of the picture could be female. When they reproduce sexually the female's
larvae are fertilised by the male and they are distributed by the tide to be
deposited to new locations.
When I first saw Jewel Anemones on the Manacles
Reef in Cornwall in 1963 their beauty just "blew me away".
Location - Raglan Rocks,
This is an unusual colour which I personally have only seen it twice at two separate
locations in Cornwall. The anemones in this picture are all same sex.
Location - Raglan Rocks -
This new larvae could be a colour different to the parents, or a mixture
of colours from the parents. The pictures below show good examples
of this. Because their larvae are dispersed by the tides all over the
British Isles you will find them anywhere below the kelp forest or on
overhanging rock faces, in caves anywhere along the west coast from the Shetland
Isles, Orkney Islands, St Kilda, the Outer Hebrides, Inner Hebrides,
west coast of
Ireland, Isle of Man, Wales, Scilly Isles, North Cornwall along the English
Channel, Western Europe down into the Mediterranean.
Pink Jewel Anemones.
Location - Bardsey Island - Llyn Peninsular, North Wales
Brown Jewel Anemones.
Location - Bardsey Island- Llyn Peninsular North Wales.
When pink and brown anemones reproduce sexually you will see the offspring
in the picture below on the left has a pink body with brown tentacles. The
anemone below right is the fusion of green and orange parents.
Location - Calf of Man- Isle of Man.
Location - Scilly Isles.
Red Jewel Anemones - all one gender.
Some have stopped feeding and withdrawn
their tentacles .
Location - Blasket Islands west coast of Island.
Green Jewel anemones with spectacular pink stinging
Location - Skellig Islands west
coast of Ireland.
Diver entering The Sgarbhstac Submarine Arch. The apex of the arch
is at a depth of 30m it then flares out to 20m wide and is 50m to the sea
bed. It is a 30m swim through 60m visibility. One of the finest
underwater dives at St. Kilda.
There are lots of magical dives around the many islands of St
Kilda the most spectacular is the Sgarbhstac Submarine Arch.
When approaching the site, which is just across from Stack Lee, you will see
rocks protruding out of the water about 20 metres high - rather drab and very
unassuming in appearance - the surprise is below the water. This is a very
exposed site and is also affected by tidal flow. You can, when conditions are
calm, swim on the surface right up to the rock face, dive down 30 metres to the
apex of the arch and enter the Sgarbhstac Submarine Arch. The view, if you
have conditions like I had, will blow your mind away - a dive you will
It is a 30 metre dive to the apex of the arch. The arch is 20 metres wide and 50 metres to the
seabed. The rock faces are covered in
many different colours of
Jewel Anemones, Plumose Anemones - pink and
white, Sponges in many bright colours - red, yellow, orange and
purple also there are Sand Eyed Anemones with yellow centres and white
tentacles. Whilst you are looking around all this beauty keep a sharp lookout
you could be visited by another air breathing animal the Grey Atlantic seal
Halichoerus grypus, which
means "hooked-nose sea pig".
Gray Atlantic Seal sleeping in one of the caves at St. Kilda
Location - Stac Lee.
The St Kilda seals are quite happy to be in close contact
with divers. Location - St Kilda Stac Lee.
In open waters gray seals rest or sleep in a vertical
position, similar to a floating bottle, the animal keeps only its head
and neck above water. Here at St Kilda they sleep in any place where they can
wedge themselves in. In this cave there are many places to use. On
this particular day there were three seals in the cave and even when they woke up they
still preferred to stay where they were wedged in, they did not want to lose
their place. This
keeps them in a safe stable place. They can hold their breath for sixty
minutes and so this in enables the seal to dive to great depths.
To capture food (dives have been recorded as deep as 1,560 feet
(475 m), with their excellent vision, hearing and very sensitive whiskers on
their cheeks which enables them to feel any vibrations in the water they are
able to find things in the dark. Seals are formidable hunters. Food sources include fish, crustaceans, squid, octopus and even occasionally
seabirds. Smaller fish are generally consumed underwater whilst larger fish
are brought up to the surface to be the broken into smaller pieces using the
seals' "prehensile" front flippers and mouth. They consume between 4% and 6%
of their bodyweight per day.
With excellent vision and hearing, very sensitive whiskers on
their cheeks this enables them to feel any vibrations from the water.
Location - St Kilda Stac Lee.
Males can also be distinguished from females by their
long-arched "roman" nose. The male nose is the basis for its Latin name. The
Gray Seal pups in the eastern Atlantic Ocean are born during September-November
whilst pups in the western Atlantic Ocean are born during January-February.
The mother feeds the pup for three weeks and then she abandons them. The
female will mate with a male then leave The grey seals at St Kilda are
very playful and curious they will approach divers and look through your mask, some
will get hold of your fins carefully with their teeth and spin you
around. They will also give you a fabulous display of their underwater
acrobatics. Their abilities will make you feel inadequate.
The grey seals at St Kilda are very playful and
curious they will approach divers and give you a fabulous display of their
Location - St Kilda Stac Lee.
Looking up vertically. Location - St Kilda Stac Lee.
We are going to make our way back up to shallower depths now. On the rock surface we
meet yellow Breadcrumb Sponges
Cliona celata, this animal
has the ability to bore into rock, also there are Pink
Plumose Anemones feeding.
Plumose Anemone. Location - St
Kilda Stac Lee.
Basking sharks head and the pectoral fin with the mouth closed, it is just
possible to make out the sharks eye.
Location - Part Erin, Isle of Man.
Plankton containing Salps - Salpidae they feed on items
of phytoplankton, they strain the water with internal filters. Location - Village Bay, St Kilda.
Basking Sharks Cetorhinus maximus
- the second largest fish in the world they can get to lengths of 11 metres
and can weigh up to 10 tons. The Basking Shark gets its name because, when
feeding, its dorsal fin and tail fluke will be out in the fresh air. This is
because the plankton is attracted to the surface by the sun. In the old days
people used to think the basking shark was sunbathing when, in reality, it
is feeding on the thickest layer of plankton.
Very often the water is murky
because of the plankton bloom - the very thing they are trying to feed on.
open-mouthed at the surface, filtering out plankton. Every hour the basking
shark passes up to 395,000 gallons (1.5 million litres) of seawater through
the huge gills that almost encircle its head. The shark is equipped with
five sets of gills on each side of its head, the ten gills slits also each
have a set of gill rakes - they are like combs and are to filter the
plankton out of the water. Once the gills are blocked with food the shark
closes its mouth, swallows the food and proceeds to carry on feeding.
liver runs the length of the abdominal cavity and is filled with oil to aid
buoyancy. Sadly, in the past it was hunted and great numbers were killed for
their livers. Because of this activity shark numbers tumbled however, fortunately for
the shark, it is now fully protected in British Waters. To dive with a
fully grown Basking shark is something you never forget, I'm fortunate to
have dived with them on many occasions. If you are ever considering
swimming with basking sharks please think again,
I would recommend that you don't unless you are fully kitted as a diver with
all the normal safety equipment with you, the reason it can be
dangerous, although the shark is harmless, is because of the places they swim
through looking for plankton they often pick up anglers fishing lines it can
get wrapped around their tails trailing behind in big loops and in
the plankton particularly, the lines are totally invisible if you where to
get tangled in the fishing line the basking shark would feel you moving the
shark would panic and dive if he had no knife to cut the line it could a
rather nasty end.
When you're sitting in the plankton bloom its like being in a fog and, as
this monster looms out straight at you, when it sees you it is quite
startled and quickly closes its mouth and turns away. After it has gone
past you it calmly opens its mouth and carries on feeding. The shark swims
in loops in a figure of eight. This behaviour keeps the shark in the
densest part where the plankton is. Basking Sharks arrive in UK waters
in approximately the month of May into the English coastal water of west and north coasts
of Devon and Cornwall. Then they move slowly northwards congregating
around the Isle of Man during the month of June, then they move on through the Irish sea
and along the west coast of Scotland up
to the Outer Hebrides and St Kilda the following the plankton.
Basking sharks front portion, head up to the dorsal fin and
pectoral fins looming out of murky plankton bloom.
Location - near Kynance Cove Cornwall
Basking sharks rear portion, from dorsal fin down to the tail
Location - near Kynance Cove Cornwall
Basking sharks mouth half open, we can see the eye and the
interior of the ten gills.
Location - Ailsa Craig near Turnberry Point
Basking sharks mouth open, we can see the interior of some of
the gill rakes.
Location - Ailsa Craig near Turnberry Point