The North Sea, Our Living Sea An introduction to life within the North Sea and the resources it provides us

Kelp Forest Common StarfishCrystal Sea Slug

Protecting Wildlife for the Future

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Chris

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The North Sea

Years of exploitation have led to the perception of an empty and lifeless North Sea, but take the time to delve below

the surface and you’ll find an astonishing array of weird and wonderful creatures.

Hidden beneath the waves is an astonishing range of wildlife. Habitats include Europe’s largest chalk reef, dense

forests of kelp, vast sandy plains, impressive rocky reefs and huge networks of submerged and semi-submerged sea

caves. All of these support a diverse range of species, from the encrusting sponges, brightly coloured corals and

anemones, scuttling crabs and lobsters, to creatures that dart and dive through the water. England’s largest colony of

grey seals thrive here, whilst hundreds of thousands of seabird arrive each summer to breed along the North Sea’s

coastline. The North Sea is also rich in resources, many of which we use in our day to day lives. Fishing, extractive

and renewable industries are all vying for space, whilst the North Sea’s waters are amongst the busiest in the world for

shipping traffic. We need to find a balance to ensure our marine wildlife is protected and that the sea continues to

provide us with the everyday resources we need.

Life in a rockpool – Kirsten Smith

No matter how far inland we live, the seas resources play a major role in our daily lives, through…

Fishing

When one of the nation’s favourite dishes is fish and chips, you can’t

help but feel a connection with the sea, no matter how land-locked

you may be. According to Seafish, the authority on seafood, UK fish

and chip shops sell over 250 million portions of fish a year! The

coastal fishing communities of the North Sea once thrived through

catches of cod, herring, lobster and even tuna. Sadly though,

overfishing and mismanagement have led to a serious decline in both

North Sea fish stocks and the associated fishing industry.

Fish is an extremely healthy source of protein, but the majority of the

fish we eat are wild caught animals. We therefore have to protect and

manage stocks in order to maintain a healthy, sustainable supply. It is

our responsibility to ensure we eat sustainably caught fish. Many

supermarkets now label their fish with details as to how they were

caught and where they were caught from, with many aiming to source

as much of their stock as possible from sustainable or accredited

schemes within the next few years. By choosing carefully which fish

you buy, you can play a part in helping our ‘living marine resources’

on a road to recovery.

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To ensure you buy fish from sustainable

sources, buy those certified by the Marine

Stewardship Council.

No matter how far inland we live, the seas resources play a major role in our daily lives, through…

Marine Aggregates

Marine aggregates, sand and gravel extracted from the sea, form the basis of the houses we live in and the pavements we

walk on. Significant quantities are landed into Tyneside, Teeside and Humberside and are mainly destined for the

construction industry. Aggregates are extracted using a suction pipe which vacuums up seafloor sediments within a

specially licensed area. These are then deposited into the ships hold, sorted, and the unsuitable material discarded back

into the sea.

Marine aggregates are an extremely important resource, with the UK industry being one of the largest in Europe. However,

marine aggregates are a finite resource and their extraction is not without its environmental impacts. The large scale

removal of sediments not only causes the removal of living organisms, it also alters the topography of the sea floor. If sand

is locally available, areas where extraction has occurred can recover relatively quickly. The biology of organisms that live in

such sediments is not fully understood, and only now are we looking at how such communities recover following the

cessation of dredging at particular sites. Areas of suitable sediments may also be important spawning and nursery areas

for many commercially important fish species.

Plaice – Mark Thomas

No matter how far inland we live, the seas resources play a major role in our daily lives, through…

Renewable Energy

The UK government has pledged an 80% reduction in carbon emissions by 2050. Renewable energy is set to help meet

this target. It is hoped that 25% of the UK’s energy will be produced from offshore wind farms by 2020. The UK also has

huge potential for developing tidal and wave energy. Offshore wind farms bring both advantages and disadvantages and

choosing their location requires considerable data and knowledge of marine ecosystems in order to minimise damage

caused both directly and indirectly to the marine environment. Effective and thorough Environmental Impact Assessments

are essential in striking the balance between our renewable energy needs and our impact on the environment.

Gibraltar Point – Robin Cosgrove

No matter how far inland we live, the seas resources play a major role in our daily lives, through…

Recreation

Alongside supplying important resources, the marine

environment also has huge recreational value. Walking, bird

watching and rock-pooling help give us a brief insight into this

unique environment, whilst SCUBA diving allows us to fully

immerse ourselves below the waves.

Programs such as Seasearch use volunteer divers to survey

the marine environment and help collect vital survey data. This

data can help us identify sites of high marine diversity or

complex habitats, alongside recording the presence of

fascinating marine creatures.

The following guide provides just a small glimpse into the

fascinating world beneath the North Sea’s waves.

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Rocky Reef

Rocky reefs are a key feature of the Northern North Sea marine environment,

forming an important part of the underwater seascape. Crabs inhabit cracks

and crevices whilst anemones, algae and sea firs anchor themselves to the

surface of rocks. The North Sea’s rocky reefs are as alive and diverse as any

tropical coral reef.

Rocky substrate provides a solid base for a whole host of unique creatures

such as sponges, soft corals and tube worms. Seaweed is often found

associated with rocky reef, secured to rock surfaces by holdfasts. Kelp, in

particular, often forms dense forests here.

Many creatures live on the reef, seeking both protection and a ready supply of

food. Hermit crabs, sea slugs and starfish hunt for prey such as sea anemones,

brittlestars and worms, whilst edible sea urchins graze upon algae. Wrasse,

blennies, rockling and scorpion fish hide amongst crevices and seaweed, their

cryptic colouration camouflaging them from predators.

Rocky reefs are of considerable conservation importance due to the immense

diversity they support.

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Kelp Forest

Kelp is a general term used to describe the large brown seaweeds that form

‘underwater forests’. Kelp attaches itself to hard substrate, such as rock, by

a holdfast, a dense bundle of branching rootlets.

These forests provide a unique habitat, food source and offer protection to a

wide range of marine creatures. Red seaweeds are often found attached to

the ‘stipe’ (or stem) of the plant, sea mats cover the ‘fronds’ (or leaves) and

mussels, sea anemones and sea squirts often live amongst the holdfast.

Sea urchins graze the algae that attaches to kelp and blue-rayed limpets

are often found feeding directly on the kelp itself. Kelp forests also provide

shelter and important nursery areas for many species of fish. Up to 220,000

juvenile fish have been recorded as sheltering in a single hectare of Kelp.

Kelp has a vital role in maintaining the health of our seas. It is fast growing

and when it dies and decays leaves behind huge amounts of organic

matter. This matter then acts as a food source for single-celled animals and

bacteria, which are then consumed by filter feeding invertebrates.

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Sand and Gravel Plains

Subtidal sand and gravel is the most widespread undersea habitat found within the UK. While the sediments to the west

of the UK are derived from shell material, here in the North Sea, sediments are primarily derived from rocky material.

What on the surface appears to be a barren wasteland is in fact a unique habitat rich in highly specialised marine life.

These vast plains are the domain of the ‘infauna’. Infauna are categorised as the animals that live within the seafloor

sediments as opposed to the water column. Worms, molluscs and crustaceans dominate here, whilst huge shoals of

sandeels crowd the waters, diving headfirst into the sediment at the slightest hint of danger. Larger predatory fish, such

as cod and thornback ray, scour these marine deserts, hoovering up food from just below the sea floor.

North Sea gravel beds were laid down during the last ice age and now form important spawning areas, particularly for

herring. The eggs are fertilised before falling to the seafloor and adhering to stones. They remain here until the eggs

hatch into free swimming larvae. Such areas provide resource rich grounds for the aggregates industry, with extracted

sand and gravel destined for the construction industry.

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Hangers on

Many marine creatures, whether found in a rockpool or at depth spend their

lives attached to hard substrata, such as rock. Rocks can provide creatures with

a firm anchor, particularly in areas of strong current, allowing them to project out

into the water column and filter feed. Through cracks and crevices, rocks also

provide shelter from predators or from the elements.

Common rock-dwellers include soft corals, anemones, molluscs (such as

mussels), barnacles and the fascinating Lightbulb Sea Squirt. These tubular

animals live in colonies ranging from 3 to 300. They attach themselves loosely

to rocks and begin growing from an overwintering bud. When sea squirts

reproduce during the summer months, they release a huge amount of larvae in

just a few hours. Sea squirts are filter feeders, removing plankton and detritus

from water which they pump through their bodies. When larvae, sea squirts

possess a simple backbone which helps them swim. They are therefore

Chordates and belong to the same animal group as you and I.

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Did you know?

Dead Man’s Fingers is actually a soft coral, composed of many individual structures,

called ‘polyps’. These polyps form fleshy lobes, which are often finger-like in shape,

giving the creature its name.

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Seabed dwelling species

Sand and gravel plains are the most widespread marine habitat found within the North Sea. The Dogger Bank, located off

the Yorkshire coast is a key example of this. This vast underwater desert stretches for 300km and ranges in depth from

18m to 40m.

Creatures found associated with sand and gravel habitats are adapted to life living on, or buried within the sediment.

Many of the invertebrates are filter feeders, extracting material from the water around them using extensive tentacles,

while many of the fish have cryptic coloration to help camouflage against predation. Plaice can be distinguished from

other flatfish by the characteristic orange spots on the upper side of the body. All flatfish are born looking like

conventional fish with the body positioned vertically and an eye on either side of the head. As development continues,

one eye migrates towards the other, resulting in the plaices rather twisted facial expression.

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Creatures that wander

Many marine creatures are highly mobile, regularly

moving location. In the case of the hermit crab this

includes moving house. As their old shell becomes too

small they must search the local area for a new,

bigger ‘home’.

Many echinoderms (starfish, sea urchins, sea

cucumbers) move using structures called ‘tube feet’.

In the case of starfish, these are small tubular

projections located on the underside of the arms and

are often arranged along grooves. ‘Tube feet’ work by

using hydraulic pressure.

Creatures such as sea slugs not only have the ability

to move along the seafloor, but also have the ability to

swim to help escape predation. When swimming sea

slugs often appear as if ‘in flight’, gracefully moving

through the water.

Did you know?

Starfish have an excellent sense of smell. Using ‘chemoreceptors’ located underneath their skin, they follow scent trails left by prey. They

can even determine the direction of their prey’s escape!

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Did you know?

Lobsters are

generally blue in

colour and only turn

red when cooked.

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Crabs and Lobsters

These crustaceans are common

throughout the North Sea and are

often found hidden within rocky

cracks and crevices. Crab and

lobster fisheries occur throughout the

North Sea region, with some areas of

the North East and Yorkshire still

using traditional Coble boats. The

distinctive flat-bottomed, high-bowed

shape of these boats allows them to

be launched and landed on shallow,

sandy beaches.

Norfolk in particular is a well known

home of the Edible Crab, otherwise

known as the ‘Cromer’ crab.

JellyfishJellyfish are free-swimming creatures belonging to the Phylum Cnidaria (this group includes the anemones).

They are found in every ocean, from the surface waters to the deep sea. Moon jellyfish are one of the most

common jellyfish seen in the North Sea. Their most distinctive feature is the presence of four horseshoe

shapes that are visible through the transparent bell. These are in fact reproductive organs. Unlike other

jellyfish, the tentacles are relatively short and do not possess a powerful sting. Lion's Mane Jellyfish are the

largest of our UK jellyfish, and can reach up to 50cm in diameter, with tentacles extending up to 3 metres from

the creatures’ body. These jellyfish have a powerful sting. When tentacles become detached from the body

they can often retain their stinging potential.

Did you know?

Jellyfish do not posses any of the following: brain, respiratory, excretory or circulatory systems

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Weird and wonderful

The North Sea is home to many charismatic species of fish.

These include the Tompot Blenny; a colourful, inquisitive little

fish with a clown’s face and scarlet ‘antlers’; and the brightly

coloured Cuckoo Wrasse. Cuckoo Wrasse have the amazing

ability to change sex! All are born as females, with only a few

later developing into males. A male will maintain a harem of

females and if he dies the dominant female will gradually

change into a male and take over the harem!

The North Sea is also home to one of our most fearsome

looking fish, the Wolf-fish. Britain is about as far south as you

are likely to find Wolf-fish, which thrive in cold northern waters.

The North Sea is a ‘hotspot’ for this species, with the costal

waters off Berwickshire supporting good numbers. Their large

head and strong jaws, combined with sharp teeth, are perfectly

designed to devour crabs, squat lobsters, molluscs and sea

urchins with ease. Adults tend to live in deeper water than the

juveniles, occurring at depths of 100 to 500 metres.

Did you know?

Wolf-fish can grow to 1.2 metres in length.

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Seals

The North Sea is home to both Grey and Common seals, and both breed

here. A key difference when identifying the two species is the appearance of

the nostrils. In the Common Seal, the nostrils form a `V’ shape, whereas in the

Grey Seal they appear almost vertically parallel.

The Common Seal is one of the smallest seal species in the World and has a

global distribution, whilst the Grey Seal is only found in the North Atlantic.

Three distinct populations occur, one in the western Atlantic, one on the

eastern Atlantic and one in the Baltic Sea. The UK is home to around 40% of

this world population and 95% of the EU population occur around our shores.

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Did you know?

Lincolnshire is home to one of England’s largest colony of breeding grey

seals. Each winter, over 1100 cow seals arrive at Donna Nook to give birth to

a single, white pup.

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The North Sea coast is a great place from which to view seals,

both hauled out and breeding. Whether you are in the North East,

North or East Anglia you are never far away from these

magnificent creatures.

Cetaceans

Most people think of whales and dolphins as living in distant oceans, but there are at least 23 cetacean species that

frequent British waters.

Generally animals over 4 - 5 metres in length are known as whales, while smaller animals are called dolphins and

porpoises. Porpoises can be distinguished from dolphins by their smaller stubby bodies and lack of a visible snout, or

beak. Porpoises also have a small triangular dorsal fin, while dolphins have a larger, more curved dorsal fin. The

Common Porpoise (Phocoena phocoena), also known as the Harbour Porpoise is frequently sighted within the North

Sea and are often seen from the coasts of Northumberland, Yorkshire and Lincolnshire. They occur in small groups and

rarely grow more than 2 metres in length.

Harbour Porpoise - Colin SpeedieBottlenose Dolphin – Paul Carter

Life in a rockpool

Rockpools and rocky shores support a wealth of marine biodiversity and are accessible to everyone. Brown, green and

red seaweeds drape over the rocks, providing shelter for creatures such as prawns, gobies and butterfish. Shore crabs

hide in cracks and crevices, waiting for unsuspecting prey, whilst anemones and molluscs cling tightly onto rock

surfaces. Life in the ‘intertidal’ (the area exposed between high and low tide) is a harsh existence and subject to

constant uncovering by the moving tide. As a result many species living here have adapted special methods to cope

with such changes. Limpets create themselves ‘homes’ on rock surfaces, small circular grooves that allow them to ‘lock’

down tightly when the tide goes out, thus preventing their moist bodies from drying as a result of exposure to the sun

and air. Limpets always return to their own ‘home-scars’ after feeding.

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Life on a sandy shoreA sandy beach is composed of minute grains of sand, crushed shells or rock. Wind and water reshape sandy beaches on

a daily basis, making such areas a challenging place to live. To compete with changes in habitat structure and exposure

to the elements, many of the creatures found here are adapted to life beneath the sand. This requires the ability to

burrow, to retain water and to breathe air. Many species do this by having bodies in enclosed structures which can retain

moisture. The most commonly found example of these are the ‘bivalve molluscs’, creatures such as cockles and

razorshells, which can clamp their shells tightly shut.

The Masked Crab, can be found buried in sediment from low water to depths of up to 100m. It uses its legs to tunnels

backwards, making a burrow in which to conceal itself. If found take some time to look at the crabs antennae. Whilst

buried these are brought together and act as a respiratory tube, allowing it to continue breathing air from the surface

whilst buried.

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Seabirds

Each summer, the North Sea supports a huge number of

breeding seabirds. The cliffs of the northern North Sea

support vast colonies of Guillemot, Razorbill, Kittiwake and

Shag, whilst the Puffin makes use of offshore islands and

coastal cliff tops.

England’s only mainland breeding colony of Gannet occurs

in Yorkshire, while a significant proportion of our rarest

breeding seabird, the Roseate Tern, breed in

Northumberland.

The sandy and shingle beaches of the southern North Sea

support further tern species, including the majestic

Sandwich Tern and our second rarest seabird, the Little

Tern. Fulmar, Herring Gull, Lesser Black-backed Gull,

Greater Black-backed Gull, Arctic Tern and Common Tern,

amongst others, also breed along the North Sea coastline.

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Did you know?

Arctic Terns migrate between the Antarctic pack ice and

Northern breeding grounds, a round journey of some 22,000

miles. On average an Arctic Tern will fly 500,000 miles in its life

time, the equivalent of travelling to the moon and back.

The Future of Marine Conservation

Our seas support and enhance our quality of life, providing us with resources (food, oxygen, materials for construction) as well as

a place to relax. But what are we doing to protect them for the future? Continued over-exploitation will leave behind a barren

wasteland; brightly coloured reefs will become devoid of wildlife; and fish suppers will become a rarity.

During 2009 the Marine and Coastal Access Act brought in new laws, allowing the creation of a network of Marine Protected

Areas (areas where human activity can be restricted to varying degrees) in English and Welsh inshore and offshore waters. In

addition to the UK Act, the Marine (Scotland) Act passed into law in 2010. This has similar objectives to the UK Act and applies to

Scottish waters. The final piece of the legislative jigsaw – a Marine Act for Northern Ireland – is expected in 2012.

Marine Protected Areas are a tried and tested means of safeguarding important marine habitats and wildlife. They protect wildlife

within their boundaries and allow nature to recover and thrive as well as offering some overall benefits to the health of the marine

environment as a whole.

The Wildlife Trusts Vision for ‘Living Seas’

The Wildlife Trusts believe that the seas around the UK have the potential to become among the most productive and wildlife-rich

on Earth. Within Living Seas:

• Wildlife and habitats are recovering from past decline as our use of the seas’ resources becomes environmentally sustainable.

• The natural environment is adapting well to a changing climate, and ocean processes are helping to slow down climate change.

• People are inspired by marine wildlife and value the sea for the many ways in which it supports our quality of life.

The Wildlife Trusts believe it is possible to achieve Living Seas around the UK within 20 years – a single generation – but only if

opportunities are seized now to make radical changes.

Help us to achieve Living Seas by visiting www.northseawildlife.org.uk and finding out the various ways in which you can get

involved.

Join us on our journey towards Living Seas

• Get outside and explore the marine environment, tell others about it or by visiting The Wildlife Trusts websites and learning

more about what there is to see and do on the coast,

• Send us underwater photographs and stories about the sea,

• Visit a coastal nature reserve,

• Take part in an event or volunteer survey and help us to gather information highlighting marine wildlife in need of protection,

• To receive quarterly newsletters with the latest up-to-date information on The Wildlife Trusts’ North Sea Marine Protected

Areas Project, email ‘subscribe’ to marine@ywt.org.uk.

Find out more about Living Seas by visiting:

www.wildlifetrusts.org.uk

www.northseawildlife.org.uk

To find out more about undertaking marine life dive surveys visit www.seasearchne.co.uk

and www.seasearcheast.org.uk

Supported by The Esmée Fairbairn Foundation