Norfolk's Unique ReefAn exploration of Europe's longest chalk reef, just off the North Norfolk coast

Photographed by Dawn Watson and Rob Spray Photographed by Dawn Watson and Rob Spray

Protecting Norfolk's Wildlife for the Future

North Norfolk's Amazing Chalk ReefFew visitors notice the beautiful chalk reef that lies so close to the North Norfolk shore. The sliver of this rich marine habitat which can be seen exposed at low tide gives just a subtle clue to its amazing history and biodiversity. This chalk is the product of millions of years of geological construction which has turned unimaginable numbers of plankton fragments into a sheet of limestone rock up to 460m thick. It stretches across Britain from Yorkshire in the north, to Kent in the south and to the white horse hill carvings of Wiltshire in the west.

The production of this rock started around 100 million years ago, in the Cretaceous period when the Earth was a very different place. An atmosphere rich in oxygen fostered some spectacular species, such as dragonflies with wingspans of over a metre! Volcanic carbon dioxide had created a greenhouse effect. There were no ice caps and what was to become Britain was covered by a tropical sea.

This warm water was home to a massive population of minute, floating football-shaped algae. This phytoplankton harvested carbon from the atmosphere and shed it as tiny plates (called coccoliths). These built up over millions of years into a thick layer of chalk. Not only did this create our reef but the huge amount of carbon this captured and locked away resulted in the comfortable climate we have now. Our unsustainable exploitation of fossil fuels is now undoing the plankton's good work, threatening hotter and more unstable weather.

Little Cuttlefish – Sepiola atlantica – 50mm/2 inches longMature little cuttlefish are only the size of a bumblebee but they will still face up to divers - staging a threat display - before jetting away leaving a decoy blob of swirling black ink.

Surprisingly these clever, complicated animals are molluscs, related to snails. They are an advanced sub-class along with the squid and octopus.

Members of this class are known as the cephalopods, meaning 'head feet'. It is easy to see why; with versatile tentacles placed around their beaked mouths.

Looking closely at the picture you'll see the coloured dots (chromatophores) that allow them to vary their colour and pattern. The dots change in size; spread to fill areas or contract to disappear completely.

What is a reef?Most people think of tropical coral when they hearMost people think of tropical coral when they hear the word 'reef' but rocky reefs can be just as exciting.the word 'reef' but rocky reefs can be just as exciting. Sailors use reef to describe any obstruction but thereSailors use reef to describe any obstruction but there is no single, simple definition and so it can meanis no single, simple definition and so it can mean practically any raised area of solid seabed.practically any raised area of solid seabed.

Norfolk'sNorfolk's chalk reefchalk reef is an areais an area of rockof rock distinct from its surrounding seabed which forms a fantastic,distinct from its surrounding seabed which forms a fantastic, biodiverse habitat. It isn't uniform, in fact it is very variedbiodiverse habitat. It isn't uniform, in fact it is very varied allowing it to provide a foundation for a complex ecosystem.allowing it to provide a foundation for a complex ecosystem. It's like an underwater town or city with a busy centre,It's like an underwater town or city with a busy centre, sprawling suburbs and surrounded by a wide open space thatsprawling suburbs and surrounded by a wide open space that buffers it from other habitats.buffers it from other habitats.

A varied terrain supports a wider range of species than oneA varied terrain supports a wider range of species than one which is bland. Every different niche has its own residents.which is bland. Every different niche has its own residents. Animals, like people, prefer different types of homes and theAnimals, like people, prefer different types of homes and the chalk provides housing for many hundreds of species.chalk provides housing for many hundreds of species.

We have only just started to appreciate how varied the life ofWe have only just started to appreciate how varied the life of the reef is. There are animals on our reef which have notthe reef is. There are animals on our reef which have not been seen anywhere else in the world.been seen anywhere else in the world.

Dahlia Anemone – Dahlia Anemone – Urticina felina Urticina felina – 150mm/6 inches across– 150mm/6 inches acrossMany anemones are dainty but the dahlia is big and colourfulMany anemones are dainty but the dahlia is big and colourful just like its floral namesake. It is tougher than most and canjust like its floral namesake. It is tougher than most and can live down on the seafloor. It often looks as though it is plantedlive down on the seafloor. It often looks as though it is planted in sand but always secures itself to a stable hard objectin sand but always secures itself to a stable hard object beneath the surface with its big sticky foot or basal disc.beneath the surface with its big sticky foot or basal disc.

The horseman anemone looks veryThe horseman anemone looks very similar but it is simple to tell them apart.similar but it is simple to tell them apart. The dahlia has a sticky stalk which picksThe dahlia has a sticky stalk which picks up stones when it retracts for extraup stones when it retracts for extra protection while it is closed (above).protection while it is closed (above).

An anemone is a single polyp, related toAn anemone is a single polyp, related to corals where hundreds of polyps livecorals where hundreds of polyps live together in a communal structure. together in a communal structure. Anemones as a whole are also namedAnemones as a whole are also named after the garden flower, which just goes to show how firmly our thinking is planted on dry land.after the garden flower, which just goes to show how firmly our thinking is planted on dry land.

Cley – Clay ridges and the start of the chalk reefCley marks the start of the chalk reef. ItCley marks the start of the chalk reef. It emerges from under a thick layer of clayemerges from under a thick layer of clay which was carried in by glacial ice flowswhich was carried in by glacial ice flows and deposited during subsequent melts. and deposited during subsequent melts.

During glacial periods (ice ages) far moreDuring glacial periods (ice ages) far more of the world's water was frozen and seaof the world's water was frozen and sea levels were very much lower. Britain waslevels were very much lower. Britain was linked to Europe by an area now known aslinked to Europe by an area now known as Doggerland. When the last ice age endedDoggerland. When the last ice age ended around 10,000 years ago melt water fromaround 10,000 years ago melt water from retreating ice started to form the Northretreating ice started to form the North Sea. We were finally separated from theSea. We were finally separated from the continent about 6,000 years ago.continent about 6,000 years ago.

The clay is reef-like with ridgesThe clay is reef-like with ridges running east-west which are morerunning east-west which are more than a metre high. The hard claythan a metre high. The hard clay hosts static anemones andhosts static anemones and sponges as well as burrowingsponges as well as burrowing crustaceans and boring molluscs.crustaceans and boring molluscs.

Clay is a good habitat, but theharder surface of the chalk is more stable and allows even more animals to establish themselves as it extends to the east.

Plumose Anemone – Metridium senile – up to 30cmThe tallest anemone in UK waters, plumose anemones can grow to 30cm/12 inches tall. However even a large example can collapse down to almost nothing if it chooses. Anemones are simple animals which draw in water to inflate themselves – to reach out high into the strongest currents to feed on passing particles.

The duster like plume of 200-300 tentacles are a trap for food particles and small animals.

They appear to be sticky as they contain thousands of stinging cells which fire tiny tethered harpoons into anything that touches them.

Plumose anemones prefer to feed in the fast moving water high above the seabed so they appear on tall outcrops of chalk and also cover many shipwrecks. They compete for this position with the dead man's finger soft coral, which also comes in white and orange like the plumose.

Salthouse – A secret seascape

Salthouse beach doesn't offer any clue at all to theSalthouse beach doesn't offer any clue at all to the areas of chalk which are so close to shore. The steepareas of chalk which are so close to shore. The steep gravel beach continues underwater down to a craggygravel beach continues underwater down to a craggy area which we have only just started to explore. Thearea which we have only just started to explore. The water here deepens more quickly than at other sites –water here deepens more quickly than at other sites – but much depends on the movement of sand andbut much depends on the movement of sand and gravel underwater during winter storms.gravel underwater during winter storms.

Dives at exposed beaches like Salthouse have to beDives at exposed beaches like Salthouse have to be planned carefully as fierce currents can run along theplanned carefully as fierce currents can run along the coast. Divers use tide tables to predict the best andcoast. Divers use tide tables to predict the best and safest times to make detailed surveys.safest times to make detailed surveys.

Within 50m of the shore crumbling chalk channelsWithin 50m of the shore crumbling chalk channels lead to an area of seabed strewn with large shardslead to an area of seabed strewn with large shards of rock. These provide overhangs beloved by smallof rock. These provide overhangs beloved by small crabs and young lobsters as well as a top edgecrabs and young lobsters as well as a top edge which catches the current for hungry filter andwhich catches the current for hungry filter and suspension feeders which thrive here.suspension feeders which thrive here.

Further from the shore the rock fragments areFurther from the shore the rock fragments are generally somewhat smaller. Hard flint and softgenerally somewhat smaller. Hard flint and soft chalk boulders cover the bedrock to produce a lowchalk boulders cover the bedrock to produce a low lying, tide swept seascape which is encrusted withlying, tide swept seascape which is encrusted with robust static animals.robust static animals.

Small Spider Crabs – 50-100mm/2-4 inches acrossLobsters and edible crabs are the most famous Norfolk crustaceans but there are lots of others. Among the most interesting are our small spider crabs which have a real flair for fashion.

Much bigger spinyMuch bigger spiny spider crabs live onspider crabs live on the south coast butthe south coast but they aren't nearly asthey aren't nearly as stylish as the speciesstylish as the species we have locally. Therewe have locally. There are numerous smallare numerous small spider crabs on thespider crabs on the reef which adornreef which adorn themselves with plantthemselves with plant and animal material toand animal material to act as camouflage. act as camouflage.

They are often called decorator crabs, for very obviousThey are often called decorator crabs, for very obvious reasons. Many species can only really be identified from areasons. Many species can only really be identified from a clean, empty shell so they are usually simply separatedclean, empty shell so they are usually simply separated into two main groups when spotted on wildlife surveys.into two main groups when spotted on wildlife surveys.

Long legged spider crabs (Macropodia): tasselled with redLong legged spider crabs (Macropodia): tasselled with red or brown seaweed to blend in with algae (Above)or brown seaweed to blend in with algae (Above)

Sponge spider crabs (Inachus): usually covered in livingSponge spider crabs (Inachus): usually covered in living pink and yellow sponges – like a novelty sumo suit! (Left)pink and yellow sponges – like a novelty sumo suit! (Left)

Weybourne – Wreckage and wildernessMany divers think the reef starts here, although few really knowMany divers think the reef starts here, although few really know where. Some motor to explore sandy areas not realising thatwhere. Some motor to explore sandy areas not realising that there is channelled chalk close to shore, straight off the beach.there is channelled chalk close to shore, straight off the beach.These channels could have been cut by melt water running offThese channels could have been cut by melt water running off higher ground after the ice age but their rounded surfaces mayhigher ground after the ice age but their rounded surfaces may also be due to abrasion by the sand which surrounds thesealso be due to abrasion by the sand which surrounds these inshore chalk features – and harbours little cuttlefish.inshore chalk features – and harbours little cuttlefish.

The very steep gravelThe very steep gravel beach gives manybeach gives many walkers and swimmerswalkers and swimmers the impression of greatthe impression of great depth, but the seabeddepth, but the seabed levels out within 50m.levels out within 50m. Rumour of a muchRumour of a much deeper channel in thedeeper channel in the chalk here persist but itchalk here persist but it simply isn't evident at present. It may be filled by sediment,simply isn't evident at present. It may be filled by sediment, perhaps hidden by the sand gathered around the wreck of theperhaps hidden by the sand gathered around the wreck of the Rosalie which was torpedoed and grounded here in 1914.Rosalie which was torpedoed and grounded here in 1914.

There was military activity here during both World Wars andThere was military activity here during both World Wars and unspent ammunition can still be found lying on the seabed. Chalkunspent ammunition can still be found lying on the seabed. Chalk features increase in height going east from Weybourne, due to afeatures increase in height going east from Weybourne, due to a huge overlying slab of chalk stretching to West Runton.huge overlying slab of chalk stretching to West Runton.

Sea Toad – Sea Toad – Hyas araneusHyas araneus – 150mm/6 inches across – 150mm/6 inches acrossSmall spider crabs are talented decorators but the complete master of disguise is the sea toad orSmall spider crabs are talented decorators but the complete master of disguise is the sea toad or greater spider crab. This stocky spider crab may not have film star looks but it knows how to blend in.greater spider crab. This stocky spider crab may not have film star looks but it knows how to blend in.

By enthusiastically covering themselves in the animals and plants found nearby – mostly sponge andBy enthusiastically covering themselves in the animals and plants found nearby – mostly sponge and seaweed in the pictures - they disappear into their surroundings. Decorator crabs transfer theirseaweed in the pictures - they disappear into their surroundings. Decorator crabs transfer their camouflage when they moult - to grow all crabs have to shed their old, rigid shells and expand a newcamouflage when they moult - to grow all crabs have to shed their old, rigid shells and expand a new soft one underneath. Many 'crabs' found on the beach are old, empty shells rather than dead animals.soft one underneath. Many 'crabs' found on the beach are old, empty shells rather than dead animals.

Sheringham – The heart of the reefThe most rugged chalk starts north of Sheringham Park and runs east beyond Beeston Regis to WestThe most rugged chalk starts north of Sheringham Park and runs east beyond Beeston Regis to West Runton. The heart of the reef, with the most dramatic features, is off the centre of Sheringham itself.Runton. The heart of the reef, with the most dramatic features, is off the centre of Sheringham itself.The chalk is sometimes described as 'gullies', lowThe chalk is sometimes described as 'gullies', low grooves in the stone. 'Gullies' gives just a hint as togrooves in the stone. 'Gullies' gives just a hint as to the impressive features a little further out. Lowthe impressive features a little further out. Low channels deepen as they run out north from slightchannels deepen as they run out north from slight depressions into 3m deep valleys. These are cut bydepressions into 3m deep valleys. These are cut by the rising and falling tides down into a huge slab ofthe rising and falling tides down into a huge slab of chalk which has been thrust up on top of the mainchalk which has been thrust up on top of the main body of the reef by ancient glacial action.body of the reef by ancient glacial action.

Chalk isChalk is relativelyrelatively soft andsoft and continuescontinues to beto be eroded byeroded by tides, currents and humans while it provides a home totides, currents and humans while it provides a home to myriad animals. Some of the valleys end between arches ormyriad animals. Some of the valleys end between arches or tunnels inhabited by animals which are unusual in the easttunnels inhabited by animals which are unusual in the east such as leopard spotted gobies and tompot blennies. Theysuch as leopard spotted gobies and tompot blennies. They provide features tall enough to attract sheltering shoals ofprovide features tall enough to attract sheltering shoals of larger fish too – bib or pouting in the picture above.larger fish too – bib or pouting in the picture above.

Pictures of these features have helped make the North Norfolk reef better known. The North Sea isPictures of these features have helped make the North Norfolk reef better known. The North Sea is rarely seen as an exciting wildlife haven but the chalk reef is an important habitat to be proud of.rarely seen as an exciting wildlife haven but the chalk reef is an important habitat to be proud of.

Lesser Weever Fish – Echiichthys vipera – 14cm/6 inches longThese fish are seldom seen but have a fearsome reputation... it's not their fault, they are just trying to stay out of sight. Like many marine animals they really don't want to waste energy chasing food. They

hide in the sand to wait for their prey and also to avoid predators.

Unlike most fish, they don't have a swim bladder; an adaptation to this peculiar life-style.

If startled they dart away low over the sand raising their venomous dorsal fin for protection.

The chances of encountering a weever fish are very small but the effects can be agonising. Wearing footwear and avoiding shallow sand around low tide will reduce your risk. It doesn't attack but has a defence so effective that the name 'weever' comes from the French for viper. If stung, immediately immerse in the hottest water you can stand, to break down the poison, and seek medical help.

Beeston Regis – Beneath the bumpThe coast here is marked by 'Beeston Bump' which at 63m is the highest point on the coast for miles as well as being the home of the mythical dog Black Shuck. Once past Sheringham the inshore gullies and features in the chalk get gradually smaller – but no less packed with life.

To survey over the full 30km/20 mile length of the reefTo survey over the full 30km/20 mile length of the reef volunteers often dive in strong currents with a boat forvolunteers often dive in strong currents with a boat for safety cover. Divers can cover up to 3km/2 miles in ansafety cover. Divers can cover up to 3km/2 miles in an hour on a drift dive, towing a buoy to mark their position.hour on a drift dive, towing a buoy to mark their position.Seasearch and professional surveys have recordedSeasearch and professional surveys have recorded around 350 marine species on the reef but there arearound 350 marine species on the reef but there are hundreds more to be found. Surveys in 2011 found ahundreds more to be found. Surveys in 2011 found a new species of sponge which is unique to Norfolk.new species of sponge which is unique to Norfolk.

West Runton – Ancient river bed below fossil cliffs

The rockpools on the shore and the fossil rich cliffs behind offer aThe rockpools on the shore and the fossil rich cliffs behind offer a tantalising introduction to what can be found here underwater.tantalising introduction to what can be found here underwater.

Most of the reef gullies run parallel to each other out from the shoreMost of the reef gullies run parallel to each other out from the shore but at West Runton some islands of rock have been isolated. Thesebut at West Runton some islands of rock have been isolated. These are probably the result of melt water rivers cutting away the rockare probably the result of melt water rivers cutting away the rock around them after the ice age. These have exposed and often quitearound them after the ice age. These have exposed and often quite efficiently removed a particularly soft lower layer of chalk.efficiently removed a particularly soft lower layer of chalk.

A bus sized plateau has been undercut by caves and tunnels whereA bus sized plateau has been undercut by caves and tunnels where layers, which took thousands of years to build up, have eroded.layers, which took thousands of years to build up, have eroded. These overhangs and passages are a welcome refuge for fish andThese overhangs and passages are a welcome refuge for fish and many other animals from both the current and their predators.many other animals from both the current and their predators.

In these well hiddenIn these well hidden habitats there may behabitats there may be rare or unexpectedrare or unexpected creatures waiting tocreatures waiting to be discovered.be discovered.

Sea Bass – Dicentrarchus labrax – up to 1m/40 inchesLarge shoals of bass are fairly new to the region and in summer they hunt up and down the coast for food.

Bass are slow to grow and most bodies agree that the minimum catch size should be increased to allow fish to breed before they are caught.

Bass can live more than 30 years and females don't mature until they are more than 42cm (17 inches) long, which can take up to 10 years.

Bass themselves are very partial to sand eels so the sandy areas these prefer are a key habitat for a sustainable fishery. Small animals and simple seabeds often play a vital role in the food web which connects all species. Without protection their loss can upset the balance and important commercial species can quickly disappear.

East Runton – Seaweed garden of NorfolkFrom here the outer chalk plain starts to widen while the inshore chalk reverts to low polished channelsFrom here the outer chalk plain starts to widen while the inshore chalk reverts to low polished channels rather than rugged gullies. The channels are rather like those at Weybourne but shallower and stretchrather than rugged gullies. The channels are rather like those at Weybourne but shallower and stretch over a much larger area. This pale, chalk plateau gives rise to an abundance of seaweed.over a much larger area. This pale, chalk plateau gives rise to an abundance of seaweed.

During the summer vibrant red and green foliage waves in theDuring the summer vibrant red and green foliage waves in the moving water like colourful plants. Seaweeds share similarities butmoving water like colourful plants. Seaweeds share similarities but are not true plants, they don't have the same internal structure.are not true plants, they don't have the same internal structure.

The conditions are so good for seaweed that this site hosted moreThe conditions are so good for seaweed that this site hosted more species than any other surveyed in the county in 2011. Seaweedspecies than any other surveyed in the county in 2011. Seaweed is important as the foundation of a healthy ecosystem, just asis important as the foundation of a healthy ecosystem, just as plants are on land, feeding the base of the food chain.plants are on land, feeding the base of the food chain.The offshore plain isThe offshore plain is strewn with flints leftstrewn with flints left when the chalkwhen the chalk bedrock has beenbedrock has been eroded around them.eroded around them. Flint is formed byFlint is formed by silica ooze which hassilica ooze which has solidified undersolidified under pressure. Many ofpressure. Many of the rocks are 'potthe rocks are 'pot stones' – doughnutstones' – doughnut shaped formationsshaped formationsof stone also calledof stone also called

paramoudra flints. A geological mystery, they may have formed in prehistoric animal burrows.paramoudra flints. A geological mystery, they may have formed in prehistoric animal burrows.

Cromer – End of the pier showCromer's famous pier enables summer strollers to walk outCromer's famous pier enables summer strollers to walk out above the chalk – whether they know it or not! The legs of theabove the chalk – whether they know it or not! The legs of the pier form an artificial reef that leads to the real thing - sopier form an artificial reef that leads to the real thing - so wildlife is always nearby. Beneath the pier many animals livewildlife is always nearby. Beneath the pier many animals live amongst the debris left by anglers, tourists, builders andamongst the debris left by anglers, tourists, builders and fishermen. The seabed has sadly become a bit of a tip, pleasefishermen. The seabed has sadly become a bit of a tip, please don't add to the mess and dispose of your litter carefully.don't add to the mess and dispose of your litter carefully.

Foulness – Beyond the pierBeyond the pier a vast area of chalk called Foulness stretches out more than 5km (3 miles) from the beach. This expanse ofexpanse of bedrock forms a plain with banks and ridges 1-2m high. Thebedrock forms a plain with banks and ridges 1-2m high. The remains of the lost village of Shipden are spread across theremains of the lost village of Shipden are spread across the reef here. Small-spotted catsharks (often called dogfish)reef here. Small-spotted catsharks (often called dogfish) rest here while shoaling fish swirl around the natural andrest here while shoaling fish swirl around the natural and manmade reef features over a carpet of red seaweeds.manmade reef features over a carpet of red seaweeds.

Seaweeds need light to flourish and red species are dominant further out. They are adapted to theSeaweeds need light to flourish and red species are dominant further out. They are adapted to the reduced spectrum of sunlight at this depth. Green varieties grow best in the brightness of the shallows.reduced spectrum of sunlight at this depth. Green varieties grow best in the brightness of the shallows.

Mermaid's Glove Sponge – Haliclona oculata – 30cmThe tallest sponge in the east grows more than aThe tallest sponge in the east grows more than a foot high and is sometimes mistaken for fan coral orfoot high and is sometimes mistaken for fan coral or the stagshorn sponge which grows on other coasts.the stagshorn sponge which grows on other coasts. Despite this mermaid's glove is actually a quiteDespite this mermaid's glove is actually a quite distinctive animal. Whether you are lucky enough todistinctive animal. Whether you are lucky enough to see it living underwater or simply find it washed upsee it living underwater or simply find it washed up on the beach it is quite simple to identify.on the beach it is quite simple to identify.

The 'gloves' are porous and predictably spongy butThe 'gloves' are porous and predictably spongy but the key ID feature is the rows of larger holes alongthe key ID feature is the rows of larger holes along each finger. Sponges pass water in through the veryeach finger. Sponges pass water in through the very small holes in their bodies and out through the largersmall holes in their bodies and out through the larger ones. The little pores act as sieves which preventones. The little pores act as sieves which prevent them becoming clogged with particles that are toothem becoming clogged with particles that are too big for them to digest.big for them to digest.

Sponges are some of the very simplest animals;Sponges are some of the very simplest animals; without the nervous, digestive and circulatorywithout the nervous, digestive and circulatory systems we have. They are reinforced with asystems we have. They are reinforced with a substance known as spongin which also gives themsubstance known as spongin which also gives them their common name. It forms a sort of fibroustheir common name. It forms a sort of fibrous skeleton and most sponges also have a frameworkskeleton and most sponges also have a framework of tiny glassy spicules too. Spicule means 'spike',of tiny glassy spicules too. Spicule means 'spike', because many of them are needle shaped. because many of them are needle shaped.

Overstrand to Sidestrand - Sand worn seabedOverstrand is another village where those looking out to sea will have little idea of the exciting marineOverstrand is another village where those looking out to sea will have little idea of the exciting marine habitat so close by. The chalk here appears as fingers emerging from the sand as it slopes down.habitat so close by. The chalk here appears as fingers emerging from the sand as it slopes down.

This was another site whereThis was another site where the amazing little cuttlefishthe amazing little cuttlefish were recorded and also onewere recorded and also one where large numbers ofwhere large numbers of weever fish hunt, especiallyweever fish hunt, especially at night. The soft sandat night. The soft sand around the chalk suits botharound the chalk suits both of these ambush hunters.of these ambush hunters.

(left) Cuttlefish blow sand(left) Cuttlefish blow sand away to bury themselves.away to bury themselves.

(right) You can only really(right) You can only really appreciate just how smallappreciate just how small they are beside a humanthey are beside a human interloper – can you spot it! interloper – can you spot it!

If they aren't hunting all thatIf they aren't hunting all that can be seen of them is theircan be seen of them is their eyes, which they coloureyes, which they colour match to the sand theymatch to the sand they spread over themselvesspread over themselves with their tentacles.with their tentacles.

Skeleton Shrimps – Caprella spp. – 20mm/0.75 inches

Reef wildlife comes in many sizes, but if you areReef wildlife comes in many sizes, but if you are small reaching the best food can be a real challengesmall reaching the best food can be a real challenge so you have to be resourceful. One species playsso you have to be resourceful. One species plays host to another and as rough surfaces are ideal forhost to another and as rough surfaces are ideal for these tiny crustacean diners they often cover the tallthese tiny crustacean diners they often cover the tall mermaid's glove sponges on the east coast.mermaid's glove sponges on the east coast.

Skeleton shrimps have claws rather like those of aSkeleton shrimps have claws rather like those of a praying mantis and you can also see pregnantpraying mantis and you can also see pregnant females in both of the pictures if you look closely.females in both of the pictures if you look closely.

Trimingham – Chalk slips under clay, the end of the reef?At low tide bright, white chalk shows here at the water's edge. The sand here is very fine and the chalk is very soft so it is hard for all but the toughest animals to gain a foothold on the reef which starts just beyond the end of the groynes.

This is a geological transition point, with the chalk slipping back under hard clay as it runs to the east. The very mobile sand moves with the tides polishing, surrounding and often covering the hard seabed. It is difficult to say where the reef ends as winter storms can reveal or conceal more chalk.

The clay to the east is an important habitat in its own right. Animals like mussels can form extensive beds on their own but flourish on a more stable seabed too. Such animal-built (biogenic) reefs are rich ecosystems and very important to the food chains that we and many other animals depend on. Delicate seabeds such as these are easily damaged and important geological formations can never be truly restored.

The Marine Conservation Zone process aims to establish some small haven areas which let us see how these habitats would behave without human interference. Sadly this has proved controversial - a huge mussel bed to the east was destroyed by trawling after it was proposed as an MCZ.

Living Seas – Gaining protection for Norfolk’s chalk reefHealthy seas rich in wildlife are a vital part of our own life-support system. Sadly the history of how we have cared for the marine environment has often been one of damage and over-exploitation, just think of the loss of North Sea herring, which formerly supported a thriving Norfolk herring industry.

Only a tiny proportion ( less than 0.01%) of our seas have any significant protection at present. As a result we continue to see damage and decline to marine ecosystems.

The Wildlife Trusts and others are supporting the setting up of Marine Conservation Zones (MCZs) which are a new type of protected area intended to ensure our seas are managed sustainably. A network of 127 potential MCZs has been proposed following the passing of the Marine and Coastal Access Act in 2009.

Norfolk's chalk reef, because of its special habitats and diverse wildlife, has been recommended to gain MCZ protection for its future. Our reef has survived because trawling stopped more than 100 years ago to protect the crab and lobster fishing and this ban was secured as a byelaw in 1962. The current level of crab and lobster potting is considered ‘low impact’ and is unlikely to be affected by MCZ designation.

There is widespread support for the reef to become an MCZ but still we need your help to make this happen. For ways to support the campaign visit www.northseawildlife.org.uk

Where to find out moreIf you have been surprised and excited by the marine wildlife in this guide there are many ways to take your interest further. These websites will help start your search:

Norfolk Wildlife Trust holds regular coastal events and whether you are a diver or beachcomber the Trust is always keen to hear of interesting finds and sightings around our coast. The Trust's website is a great place to find out more and hear about the activities you can take part in.www.norfolkwildlifetrust.org.uk

Twelve Wildlife Trusts have teamed up to help North Sea wildlife. Their aim is to ensure that an ecologically coherent network of Marine Conservation Zones is established in UK waters. Visit their website or Facebook page to learn more about the project, the latest marine news and how to help the wildlife of the North Sea.www.northseawildlife.org.uk www.facebook.com/northseawildlife

Qualified divers are privileged to be able to visit the reef and Seasearch, a project run by Marine Conservation Society volunteers, helps them to survey and record the habitat and its residents. Divers can find out more and everyone can enjoy more photos from the reef here: www.seasearcheast.org.uk

Copyright 2012 Rob Spray, Dawn Watson and Norfolk Wildlife Trust

Protecting Norfolk’s Wildlife for the Future