Post on 31-Dec-2016
Reefs out of Plymouth (‘Prawle Point to Plymouth Reefs out of Plymouth (‘Prawle Point to Plymouth & Eddystone’): & Eddystone’): Special features and conservation Special features and conservation
needs.needs.Keith HiscockKeith Hiscock
July 2009July 2009(Presentation first given (Presentation first given
April 2009, adjusted April 2009, adjusted to support the to support the
announcement of a announcement of a draft Reef Special draft Reef Special
Area of Conservation)Area of Conservation)
This presentation is available from www.ukmpas.org/presentations.htmlThis presentation is available from www.ukmpas.org/presentations.html
Reefs out of Plymouth – special features and conservation needs• Context: 110 years of surveys, recent surveys and new ‘offshore’ SACs.
• Grand Tour – different and ‘Important’ landscapes, habitats, communities and species.
• All is not well – existing damage to biodiversity, threats to habitats and species, and conservation needs.
• Improving information resources.
• Words of comfort.
There is a long history of study of areas out of Plymouth - early work at the Marine Biological Association was directed, in part, at documenting the marine life present near Plymouth, although reef habitats were often sampled by accident.
From: Allen 1899. ‘On the fauna and bottom deposits near the thirty- fathom line from the Eddystone Grounds to Start Point.’
Kitching
Those studies continued through the 20th century (gaps for wars and until 1988, when government research policy withdrew funding from long-term studies.)
Forster
Southward & Holme
The Plymouth Marine Fauna is a valuable source of information about the species recorded out of Plymouth and, although last published in 1957, is available on-line:
www.mba.ac.uk/pmf
Surveys using diving:in the 1980’s and 1990’s commissioned by the nature conservation agencies, undertaken by Devon Wildlife Trust and, more recently the Seasearch programme.
Habitat sample points from www.searchmesh.net
Locations (square spots)in the vicinity of Plymouth that have been sampled since the 1980’s in surveys commissioned by the nature conservation agencies and undertaken by Devon Wildlife Trust and by Seasearch.
Surveys over the past 100+ years have demonstrated the Surveys over the past 100+ years have demonstrated the richness and specialrichness and specialfeatures of the features of the submerged reefssubmerged reefsout of Plymouthout of Plymouth
Hand DeepsHand Deeps
Recent survey areas to identify possible Special Areas of Conservation (EU Habitats Directive)
Outcome: Prawle Point to Plymouth & Eddystone draft SAC
Using existing information: MESH and NBN
www.searchmesh.net
MESH maps seabed types and MESH maps seabed types and the location of spot survey sites the location of spot survey sites which can be interrogated to list which can be interrogated to list biotopes but does not allow biotopes but does not allow access to survey data (which can access to survey data (which can be accessed from be accessed from www.searchnbn.net).www.searchnbn.net).
There are large areas of seabed with no spot survey data
Results of video tows during Haskoning surveys
Video images are just about sufficient to Video images are just about sufficient to identify large species and biotopes presentidentify large species and biotopes present
Video surveys underwayVideo surveys underway
Drop-down video - getting better Drop-down video - getting better (some images from later in the survey)(some images from later in the survey)
But, you still need to look with your own eyes to find hidden nuggets
Understanding the character and special features of reefs out of Understanding the character and special features of reefs out of Plymouth benefits from a long history of study, surveys Plymouth benefits from a long history of study, surveys
undertaken undertaken in situ in situ and ‘local knowledge’ of marine biologists.and ‘local knowledge’ of marine biologists.
The Grand Tour • Hatt Rock & Hand Deeps• Eddystone• Drop-off (submerged cliff-line)• West Rutts• East Rutts• Mew Stone• Fairy Land• Hilsea Point Rock• Stoke Point• Chicken Rock
Offshore reefs
Hatt RockHatt Rock
The top of Hatt Rock at about 25m below chart datum. Characteristic features The top of Hatt Rock at about 25m below chart datum. Characteristic features include a kelp park with sea fans mixed-in, common hydroids include a kelp park with sea fans mixed-in, common hydroids Gymnangium Gymnangium montaguimontagui, only occasionally seen elsewhere, and common nationally scarce brown , only occasionally seen elsewhere, and common nationally scarce brown algae, algae, Carpomitra costataCarpomitra costata..
Diving through the year enables observation of breeding seasons and changes through Diving through the year enables observation of breeding seasons and changes through the year – here, the reproductive bodies on the year – here, the reproductive bodies on GymnangiumGymnangium are seen in December are seen in December
Another remarkable feature of Hatt Rock and (to a lesser Another remarkable feature of Hatt Rock and (to a lesser extent) Hand Deeps, is the high abundance and large size of extent) Hand Deeps, is the high abundance and large size of the volcano sponge the volcano sponge Haliclona viscosa Haliclona viscosa
A series of buttresses extend out from the plateau looking like A series of buttresses extend out from the plateau looking like a granite tor, but the rock is mica-schist.a granite tor, but the rock is mica-schist.
Cliffs are universally dominated by jewel anemones, Cliffs are universally dominated by jewel anemones, Corynactis Corynactis viridis viridis
‘‘Headlands’ at Hatt Rock are characterised by plumose Headlands’ at Hatt Rock are characterised by plumose anemones, anemones, Metridium senileMetridium senile
Deep upward facing sandy rocks at Hatt Rock are characterised Deep upward facing sandy rocks at Hatt Rock are characterised by parchment tube worms, most likelyby parchment tube worms, most likely Chaetopterus variopedatus Chaetopterus variopedatus
Sea fans, Sea fans, Eunicella verrucosaEunicella verrucosa are common and often have are common and often have the rare sea fan anemone the rare sea fan anemone Amphianthus dohrniiAmphianthus dohrnii, attached, attached
An ovulid (false cowerie) mollusc found on sea fans at Hatt Rock and believed to be An ovulid (false cowerie) mollusc found on sea fans at Hatt Rock and believed to be
a species new to science – very similar to a species new to science – very similar to Simnia patula,Simnia patula, common on soft corals common on soft corals
The species most often seen on sea fans is the sea fan sea slug The species most often seen on sea fans is the sea fan sea slug Tritonia Tritonia nilsohdneri nilsohdneri – the slug above, eggs below.– the slug above, eggs below.
A chance find? The octopus A chance find? The octopus Elodne cirrhosaElodne cirrhosa
Hatt Rock is the only location on reefs out of Plymouth where Hatt Rock is the only location on reefs out of Plymouth where the cushion star the cushion star Porania pulvillusPorania pulvillus has been reported in normal has been reported in normal diving depthsdiving depths
Hand DeepsHand Deeps - in a bloom of - in a bloom of coccolithophore algae coccolithophore algae
The top of Hand Deeps is at about 8-12m below chart datum The top of Hand Deeps is at about 8-12m below chart datum with a kelp, with a kelp, Laminaria hyperboreaLaminaria hyperborea,, forest and, on shallow forest and, on shallow vertical surfaces, vertical surfaces, Sagartia elegans Sagartia elegans sea anemones, typical of sea anemones, typical of wave-exposed shallow reefs.wave-exposed shallow reefs.
Spectacular underwater landscapesSpectacular underwater landscapes
Rocks below about 25m are Rocks below about 25m are dominated by jewel anemones dominated by jewel anemones with common dead man’s fingers with common dead man’s fingers and a small variety of other and a small variety of other species. Plumose anemones occur species. Plumose anemones occur at the ‘headlands’.at the ‘headlands’.
Jewel anemones, Jewel anemones, Corynactis viridisCorynactis viridis
At about 40m, there is a boulder tumble, often with ling and At about 40m, there is a boulder tumble, often with ling and conger present, with a reduced abundance of jewel anemones conger present, with a reduced abundance of jewel anemones and extensive encrusting Bryozoa.and extensive encrusting Bryozoa.
Typical cliff scene at Hand DeepsTypical cliff scene at Hand Deeps
Back towards the top of the reef
In the shallows, there is a high abundance of wrasse especially In the shallows, there is a high abundance of wrasse especially rock cooks, rock cooks, Centrolabrus exoletusCentrolabrus exoletus
On the shallowest part of the reef, at 8m below chart datum, On the shallowest part of the reef, at 8m below chart datum, there is a mixture of dense kelp, foliose algae, encrusting there is a mixture of dense kelp, foliose algae, encrusting sponges, hydroids and elegant anemones, sponges, hydroids and elegant anemones, Sagartia elegans.Sagartia elegans.
And rarely seen species sometime turn-up on the offshore reefs. And rarely seen species sometime turn-up on the offshore reefs. This crawfish was put back This crawfish was put back and two others seen on theand two others seen on the
same dive were left in place same dive were left in place
EddystoneEddystone
Shallow reef tops where the annual kelp, Shallow reef tops where the annual kelp, Saccorhiza Saccorhiza polyschides polyschides is prevalentis prevalent
Steep rock slopes – sea fans Steep rock slopes – sea fans etc. (natural light)etc. (natural light)
Flash illuminates the foregroundFlash illuminates the foreground
Eddystone reefs are typically coated with shell sand Eddystone reefs are typically coated with shell sand (‘Eddystone gravel’)(‘Eddystone gravel’)
Sea fans, Sea fans, Eunicella verrucosaEunicella verrucosa, are especially common on , are especially common on offshore reefsoffshore reefs
Eddystone, NW reefEddystone, NW reef
Dead man’s fingers, Dead man’s fingers, Alcyonium digitatum,Alcyonium digitatum, are a soft coral common are a soft coral common everywhere: here with a bloody Henry starfish, everywhere: here with a bloody Henry starfish, Henricea Henricea sp.sp.
Red sea fingers, Red sea fingers, AlcyoniumAlcyonium glomeratumglomeratum, are less common than , are less common than dead man’s fingers: here with a seven-armed starfish dead man’s fingers: here with a seven-armed starfish Luidea Luidea ciliarisciliaris
Male cuckoo wrasse, Male cuckoo wrasse, Labrus mixtusLabrus mixtus, the most colourful British , the most colourful British fish, common at the Eddystonefish, common at the Eddystone
Back towards the top of the reef and Sagartia elegans dominate the vertical (shaded) surfaces
The sublittoral fringe at the Eddystone is dominated by The sublittoral fringe at the Eddystone is dominated by coralline algae and by the kelp coralline algae and by the kelp Alaria esculentaAlaria esculenta – a northern – a northern species no longer found on the mainland coast.species no longer found on the mainland coast.
Inshore reefs
Drop-Off (submerged cliff-line at c. 30m Drop-Off (submerged cliff-line at c. 30m depth and 2 nm south of the Breakwater)depth and 2 nm south of the Breakwater)
Amongst the forest of pink sea fans, Amongst the forest of pink sea fans, Eunicella verrucosaEunicella verrucosa, some may be white – a colour , some may be white – a colour morph that increases in proportion south of Britain and on the west coast of Ireland.morph that increases in proportion south of Britain and on the west coast of Ireland.
And, sometimes, they can’t decideAnd, sometimes, they can’t decide
A significant A significant location for rare location for rare and scarce and scarce species: football species: football sea squirt, sunset sea squirt, sunset corals, red sea corals, red sea fingersfingers
Sunset cup coral Sunset cup coral Leptopsammia pruvotiLeptopsammia pruvoti: recent research into the corals dna has shown : recent research into the corals dna has shown that individuals are clones of each other – signs of a genetically isolated population.that individuals are clones of each other – signs of a genetically isolated population.
Football seasquirts are not ‘at their Football seasquirts are not ‘at their best’ in midwinter when they lose best’ in midwinter when they lose their zooids, which start to grow their zooids, which start to grow again in about February.again in about February.
Late 2008 and early 2009 saw a large Late 2008 and early 2009 saw a large settlement of this scarce speciessettlement of this scarce species
Football sea squirt, Football sea squirt, Diazona violaceaDiazona violacea
Mashed potato sponge, Mashed potato sponge, Thymosia guerneiThymosia guernei, a scarce species frequently seen at the , a scarce species frequently seen at the Drop OffDrop Off
Axinella damicornisAxinella damicornis, a scarce sponge that is common at the Drop Off, a scarce sponge that is common at the Drop Off
Parazoanthus axinellae Parazoanthus axinellae colonising colonising Axinella damicornisAxinella damicornis
Another scarce and highly distinctive sponge:Another scarce and highly distinctive sponge: Axinella infundibuliformis Axinella infundibuliformis
A scarce and highly distinctive hydroid:A scarce and highly distinctive hydroid: Polyplumaria flabellata Polyplumaria flabellata
And plenty of ‘marine life’ for recreational divers And plenty of ‘marine life’ for recreational divers
Conger, Conger, Conger congerConger conger Lobster, Lobster, Homarus gammarusHomarus gammarus
West RuttsWest RuttsThe sort of landscape and species that characterise the reefs out of PlymouthThe sort of landscape and species that characterise the reefs out of Plymouth
East RuttsEast Rutts
Limestone rock that is peculiar for reefs out of Limestone rock that is peculiar for reefs out of PlymouthPlymouth
East Rutts reefs are rich in species and with features associated with the soft East Rutts reefs are rich in species and with features associated with the soft nature of the rock including piddock borings that in turn provide a refuge for other nature of the rock including piddock borings that in turn provide a refuge for other species. The abundance of the foliose bryozoan species. The abundance of the foliose bryozoan Chartella papyraceaChartella papyracea is unusual. is unusual.
Mew Stone
Ross, Ross, Pentapora foliacea fascialisPentapora foliacea fascialis, a fragile bryozoan, a fragile bryozoan
Pink sea fingers, Pink sea fingers, Parerythropodium hibernicumParerythropodium hibernicum – occasionally found under overhangs – occasionally found under overhangs
Peppercorn anemones, Peppercorn anemones, Isozoanthus sulcatusIsozoanthus sulcatus – often seen on Mewstone Ledges – often seen on Mewstone Ledges
Fairy Land including Hilsea PointFairy Land including Hilsea Point
Cold water kelp, Cold water kelp, Laminaria Laminaria hyperborea,hyperborea, occurs abundantly occurs abundantly
Increasing amounts warm water Increasing amounts warm water golden kelp, golden kelp, Laminaria ochroleuca,Laminaria ochroleuca, in in shallow areas in recent yearsshallow areas in recent years
Populations of the scarce solitary coral Populations of the scarce solitary coral Balanophyllia regia Balanophyllia regia occur in shallow gulliesoccur in shallow gullies
Occasional large populations of the scarce brown alga Occasional large populations of the scarce brown alga Carpomitra costataCarpomitra costata
Shallow inshore areas along the coast are host to large Shallow inshore areas along the coast are host to large populations of wrasse – here a male corkwing guards its nest populations of wrasse – here a male corkwing guards its nest of seaweedsof seaweeds
Hilsea Point RockHilsea Point Rock
Spectacular landscapesSpectacular landscapes
Hilsea Point Rock has rich sponge communities and several Hilsea Point Rock has rich sponge communities and several rare or scarce species presentrare or scarce species present
29 March 2009: same place, same stuff26 May 2007
The distinctive encrusting sponge The distinctive encrusting sponge Hexadella racroitraiHexadella racroitrai has has recently been discovered on the Hilsea Point reefs – the first recently been discovered on the Hilsea Point reefs – the first record for Englandrecord for England
The sponge The sponge Endectyon delaubenfelsi Endectyon delaubenfelsi – rarely seen on open – rarely seen on open coast reefs and more common in Plymouth Sound but a rarely coast reefs and more common in Plymouth Sound but a rarely recorded speciesrecorded species
File shells, File shells, Limaria hiansLimaria hians, build , build ‘nests’ under boulders but are ‘nests’ under boulders but are rarely seenrarely seen
Black sea cucumbers, Black sea cucumbers, Holothuria Holothuria forskaliforskali, are very common and are , are very common and are sometimes seen spawningsometimes seen spawning
Sea urchins, Sea urchins, Echinus esculentusEchinus esculentus, are ‘everywhere’ and are , are ‘everywhere’ and are important grazers, potentially clearing space for new settlement.important grazers, potentially clearing space for new settlement.
On all of the reefs, a wide range of fish speciesOn all of the reefs, a wide range of fish species
Cuckoo wrasse, Cuckoo wrasse, Labrus mixtusLabrus mixtus
Small spotted catshark (aka dogfish), Small spotted catshark (aka dogfish), Scyliorhinus canaliculaScyliorhinus canalicula, , are frequently seenare frequently seen
John dory, John dory, Zeus faberZeus faber
Tompot blenny, Tompot blenny, Parablennius gattorugineParablennius gattorugine
The leopard spotted goby, The leopard spotted goby, Thorogobius ephippiatusThorogobius ephippiatus, lives in , lives in muddy fissures and when first found on Plymouth reefs in the muddy fissures and when first found on Plymouth reefs in the 1950’s was thought to be a new species.1950’s was thought to be a new species.
More frequent reports of warm-water species in recent yearsMore frequent reports of warm-water species in recent years
Trigger fish, Trigger fish, Balistes carolinensisBalistes carolinensis
Stoke Point sponge gardensStoke Point sponge gardens
The sandy low-lying reefs off Stoke Point provide a favoured habitat for a wide range The sandy low-lying reefs off Stoke Point provide a favoured habitat for a wide range of branching and cushion sponges.of branching and cushion sponges.
Some of the sponges are nationally Some of the sponges are nationally rare or scarce speciesrare or scarce species
Nationally rare Nationally rare Adreus fascicularisAdreus fascicularis
Reef communities clear of sediment at Stoke Point – note Reef communities clear of sediment at Stoke Point – note the dog cockle shells bottom leftthe dog cockle shells bottom left
Inside the shells, the rare hemichordate Inside the shells, the rare hemichordate Rhabdopleura compactaRhabdopleura compacta
Away from the coast: Chicken Rock*Away from the coast: Chicken Rock*
* Unnamed feature – the 30m contour, with imagination, is the shape of a chicken* Unnamed feature – the 30m contour, with imagination, is the shape of a chicken
Chicken Rock has similar communities to other reefs offshore of Chicken Rock has similar communities to other reefs offshore of the coast. The widely distributed and often abundant orange sea the coast. The widely distributed and often abundant orange sea squirt squirt Stolonica socialisStolonica socialis is conspicuous is conspicuous
The occasional candidate for the cooking potThe occasional candidate for the cooking pot
The distinctive hydroid The distinctive hydroid Gymnangium montaguiGymnangium montagui is often seen on is often seen on reefs that are offshore of the coast whilst antenna hydroids, reefs that are offshore of the coast whilst antenna hydroids, Nemertesia antenninaNemertesia antennina, appear to be more common on reefs , appear to be more common on reefs towards Bigbury Baytowards Bigbury Bay
Dredging: the spoil has to be disposed of ……
All is not well – existing damage to biodiversity, threats to habitats and species, and conservation needs
Rame Head Rame Head disposal disposal
groundground
Image: Pete MessengerImage: Pete Messenger
Image: Pete MessengerImage: Pete Messenger
Reef habitats are most conspicuously impactedReef habitats are most conspicuously impacted
Dredge spoil disposal cannot be undertaken in protected areasDredge spoil disposal cannot be undertaken in protected areas
In 2001-2003, many pink sea fans In 2001-2003, many pink sea fans Eunicella verrucosa Eunicella verrucosa were were diseased and dead skeletons became covered in fouling speciesdiseased and dead skeletons became covered in fouling species
From the Plymouth Marine Fauna:From the Plymouth Marine Fauna:
Work at the University of Plymouth has identified the vibrio Work at the University of Plymouth has identified the vibrio bacteria responsible for the sea fan deaths, and, it might be a bacteria responsible for the sea fan deaths, and, it might be a natural, if unwelcome, event.natural, if unwelcome, event.
No sign of necrotic tissue on sea fans since about 2004. Whilst No sign of necrotic tissue on sea fans since about 2004. Whilst possibly a natural event, better understanding of any human possibly a natural event, better understanding of any human contribution (e.g. increased nutrient levels) is needed.contribution (e.g. increased nutrient levels) is needed.
Just a bit too close to a reef that couldn’t be ‘skipped-over’ Just a bit too close to a reef that couldn’t be ‘skipped-over’ (scallop dredge against the Drop-off)(scallop dredge against the Drop-off)
Mobile fishing gear is well-established as the greatest threat to Mobile fishing gear is well-established as the greatest threat to biodiversity on seabed habitats especially where reef species are biodiversity on seabed habitats especially where reef species are impacted. Reef habitats need to be protected from mobile gear.impacted. Reef habitats need to be protected from mobile gear.
Static fishing gear can entangle reef wildlifeStatic fishing gear can entangle reef wildlife
And, lost gear continues to fish including And, lost gear continues to fish including entangling reef speciesentangling reef species
There should be no netting on reef habitatsThere should be no netting on reef habitats
Hatt RockHatt Rock
No-one wants to lose their gear, and staying well clear of reef No-one wants to lose their gear, and staying well clear of reef habitats helps protect foraging areas for reef species and the reefhabitats helps protect foraging areas for reef species and the reef
Habitat removal (& seabed homogonization)Habitat removal (& seabed homogonization)
Outside the fishmarket in PlymouthOutside the fishmarket in Plymouth
Mobile fishing gear should be kept clear of reef habitatsMobile fishing gear should be kept clear of reef habitats
Persier
‘‘Littering’ – from metal wrecks …..Littering’ – from metal wrecks …..
To metal cansTo metal cans
Enforce the message “Overboard is over”Enforce the message “Overboard is over”(and don’t have more wars!)(and don’t have more wars!)
Removal of top predators – impacts?Removal of top predators – impacts?
Traps for crustaceans are relatively benign but removal of top Traps for crustaceans are relatively benign but removal of top predators will affect ‘naturalness’ – some areas of mpa’s should predators will affect ‘naturalness’ – some areas of mpa’s should be Highly Protected to ensure they are as close as possible to be Highly Protected to ensure they are as close as possible to natural, providing reference points and areas for recreation.natural, providing reference points and areas for recreation.
All is not lost! Some of the locations described as a result of early use of SCUBA equipment have been re-visited
The rocky subtidal communities at Hilsea Point Rock are very similar to those described over 50 years ago (Hiscock, 2005, JMBA 85, 1009-1010)
Improving information – multibeam sonar is a great start
Multibeam sonar image of reefs off Rame Head courtesy of Cefas.
Sables finesper IFREMER
The same area (boxed on the map) is registered as ‘fine sand’ on www.searchmesh.org.
Video survey gives an overall picture of habitats Video survey gives an overall picture of habitats and biologyand biology
But, to survey reef habitats for biodiversity, nothing beats getting But, to survey reef habitats for biodiversity, nothing beats getting down there!down there!
In situ In situ surveys of reef habitats by professional scientists surveys of reef habitats by professional scientists continue to be needed.continue to be needed.
The Prawle Point to Plymouth & Eddystone area The Prawle Point to Plymouth & Eddystone area has fabulous, important and sensitive marine lifehas fabulous, important and sensitive marine life
Look after it!Look after it!
Stoke PointStoke Point
See the proposals for new SACs on: See the proposals for new SACs on: www.naturalengland.org.uk/ourwork/marine/sacconsultationwww.naturalengland.org.uk/ourwork/marine/sacconsultation
Find out more about marine life and report your observations on: Find out more about marine life and report your observations on: www.marlin.ac.ukwww.marlin.ac.uk
Help to survey our subtidal areas, see Help to survey our subtidal areas, see www.seasearch.org.ukwww.seasearch.org.uk For information on dive sites, see For information on dive sites, see www.plymouthdivers.org.ukwww.plymouthdivers.org.ukPresentation available from Presentation available from www.ukmpas.org/presentationswww.ukmpas.org/presentations
Unless otherwise indicated, all images are taken by and are copyright Keith HiscockUnless otherwise indicated, all images are taken by and are copyright Keith Hiscock
The views expressed in this presentation are those of Keith HiscockThe views expressed in this presentation are those of Keith Hiscock