The Mediterranean Deep-sea Ecosystems

8/11/2019 The Mediterranean Deep-sea Ecosystems

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Lepidion lepidion( Risso, 1810)

Vincent Fossat, 1879.

Coll. Musum dHistoire naturelle de Nice.

MHNN.

The Mediterraneandeep-sea ecosystems

An overview of their diversity,

structure, functioning

and anthropogenic impacts,

with a proposal for their conservation

Ari steus antennatus

Albert Ier Prince de Monaco. Camp. scient . Pnids pl . III. 1908.

EL. Bouvier del, M. Borr el pinx.

Coll . Muse oca nographique, Monaco .


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The Mediterraneandeep-sea ecosystems

An overview of their diversity,

structure, functioning

and anthropogenic impacts,with a proposal for their conservation


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.


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Pub lished by: IUCN Centre for Mediterr ane an Coo per ation, Mlaga, Spainand WWF Medi te rranean Program me, Rom e, I ta ly

Copyright : 200 4 In terna t ional Union for Nature and Natura l Resources

Citation: WWF/IUCN ( 20 04 ) . The Mediterr ane an dee p-sea eco systems : an overview of their divers ity,s t ruc ture , funct ioning and anthro pogenic imp acts , with a p rop osa l for co nserva tion . IUCN, Mlagaand WWF, Rom e.

Part I. Cartes, J.E., F. Maynou, F. Sard, J.B. Company, D. Lloris and S. Tudela (2004). TheMedi te rranean deep-sea ecosystems: an overview of the i r d iversi ty , s t ruc ture , funct ioning andanthropogenic impacts . In : The Mediterranean deep-sea ecosystems: an overview of theirdiversity, structure, functi oning and anthropogenic impacts, wi th a proposal for conservation.IUCN, Mlaga an d WWF, Rom e. p p. 9 -38.

Part I I . Tudela S., F . Simard , J . Skinner and P. Gugl ie lmi ( 200 4) . The Medi te rr anean deep-seaecosystems: a proposa l for the i r conserva t ion . In : The Mediterranean deep-sea ecosystems:an overview of their diversity, structure, functioning and anthropogenic impacts, with aproposal for conservation. IUCN, Mlaga and WWF, Rom e. pp . 39 -47.

ISBN: 2-8317-0846-X

Layout andpr od uction by: Frano is-Xavier Bouillon, Maximed ia SARL, Cagnes-su r-Mer F-068 00 .

Pr inted by : Per fecta SARL, Villeneu ve-Lou be t F-062 70 .

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The text of this book is pri nted on recycled paper.

The designat ion o f geograph ica l enti ties in th is boo k, and the prese nta t ion o f the m ater ia l, do not imply the expr essionof any opinion whatsoever on the part of IUCN concerning the legal status of any country, territory, or area, or of itsauthor i ties , or con cern ing the de l imita tion of i ts f ront ie rs or bou ndar ies .

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Core support to the activities of the IUCN Mediterranean office is provided by the Junta de Andalucia, and the

Ministerio de Medio Ambiente,Spain.


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Acknowledgements

This docu men t has been ma de possib le thanks to the gener ous con tr ibut ion of many experts fromal l a rou nd the Medi te rranea n and overseas, who have dem onstra ted tha t core pr inc ip le of sc ienceas a too l for ra is ing the leve l of huma n u nder standing - nam ely by contr ibut ing the ir kn owledgeto the c rea t ion of a proposa l to ensure the long-te rm susta inabi l i ty of Medi te rranean deep-seaecosystems. In th is regard , the co ord ina tors wish to s incer e ly thank, in par t icular , Dr Bela Gali l,Dr Helmu t Zibro wius, Dr Angelo Turs i, Dr Cinta Por te, Dr Fra nces co Mastro totaro , Dr Phil Weaver,Dr Nria Teixidor , Dr. Giuseppe Notarbartolo di Sciara, Dr. Chedly Ras, Dr Maurizio Wrtz, andDr Graeme Kel leher , for the i r prec ious con tr ibut ions.

Special reco gnition is given to Dr Frd eric Briand , Director Gener al of CIESM, and to his team , whomade possible the organisation, jointly with IUCN, of a specific round table on the protection ofthe Medi te rr anean deep-sea wi th in the fram ework of the 2 004 CIESM congress, h e ld in Barce lona .The f ina l version of th is document , the thrust of which was out l ined there by the coordina tors ,benefi ted e nor mo usly from the ensuing d iscussion he ld a mo ngst the top leve l sc ient is ts and lega lexperts ga thered there . The coordina tors a re a lso indebted to the CIESM Workshop Monographn 23 on Medi te rran ean deep -sea ecosystems, which inspired som e aspec ts of th is docu men t .

Dr Alberto Garca, Chairman of the GFCM-SAC Subcommittee on the Marine Environment and

Ecosystems ( SCMEE) , k indly endorsed the pr esenta t ion and la te r d iscussion of a d raf t version o fth is docum ent dur ing the 200 4 m eet ing of the SCMEE.

During the last decades a consider able e ffor t ha s been mad e by diffe ren t experts in the kno wledgeof deep sea b iology of the Med iterran ean . Although we ar e still far to fully un der stand the stru ctur eand dynam ics of these par t icular ecosystems, the co odina tors wan t to ack nowledge the e ffor t m adeby the au thors to su mm arize th is kno wledge in the p resent d ocum ent . Their imp ressive sc ient ificexpertise on Mediterranean deep-sea biology affords full scientific legitimacy to the subsidiaryconserva t ion proposa ls presented here .

We acknowledge a lso Jean Jaubert and Anne-Marie Damiano from the Oceanographic Museum

of Monaco for a l lowing us to use i l lust ra t ions from the Campagnes ocanographiques duPrince Albert Ier; Brigitte Chamagne-Rollier from Nice Natural History Museum for letting us usewatercolors f rom i ts col lec t ions; Michel Huet and Pasca le Bouzanquet , In te rna t ional Hydro graphicBure au, Mo nac o; George F. Shar m an, Mar ine Geology & Geop hysics Division Nation al Geop hysicalData Center; John Campagnoli, NOAA/NESDIS, National Geophysical Data Center; Carla J. Moore,NOAA National Geop hysical Data Center and World Data Center for Marin e Geology and Geop hysics;Angelo Tursi, Dipa rtime nto di Zoo logia, Univer sit degli Stud i, Bari; Dwight Colem an, Universityof Rhode Island Graduate School of Oceanography and Rosi ta Sturm, Springer; Frederic Mel in ,Joint Research Centre of the E.C. Institute for Environment and Sustainability Inland and MarineWaters; Jean Mascle, Gosc iences Azur, Ob ser vatoire Oc an ologique de Villefra nch e, CNRS; MichelVoisset, Cather ine Satra-Le Bris and Benot Lou br ieu, Ifrem er a nd Nelly Cou rtay, Editions Ifrem er.

Thank you also to Franois-Xavier Bouillon for collecting illustrations and to Miles Heggadon forreviewing the English langu age.


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List of acronyms

CBD Con vention on Biologica l Diver sityCIESM Intern ational Com mission for Scientific Exploration of the Mediterr ane an SeaCMIMA Centr e Mediterr ani dInvestigacions Marine s i Amb ientalsCSIC Con sejo Super ior de Investigacione s CientficasDHAB Deep Hyper saline Ano xic Basin

EEZ Exclusive Econo m ic ZoneGEBCO Genera l Bathym etric Char t of the Ocean sGFCM Genera l Fisher ies Com mission for the Mediterr ane anGFCM-SAC GFCM Scien tific Adviso r y Com m itteeGFCM-SAC-SCMEE GFCM SAC Sub-Com m ittee on Marine Environ m en t an d Ecos ystemsICES Intern ational Cou ncil for the Exploration of the SeaISA Intern ational Seabed Autho rityIUCN The World Con ser vation UnionMCPA Marin e and Coas tal Pro tected Area sMPA Marin e Pro tected Area sPOM Par ticulate Organ ic Matter

RFMO Regional Fisher ies Managem ent Organ isationSPA Pro tocol Specially Pro tected Area sSPAMI Specially Pro tected Area s of Mediterr ane an Intere stUNCLOS United Nation Con ven tion on the Law of the SeaUNICPOLOS United Nations Open -end ed Inform al Con sultative Pro cess on Ocean s and the Law of the SeaUN GA United Nations Gener al Asse m blyWSSD World Summ it on Sustainable Developm entWWF World Wide Fund for Natur e


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TABLE OF CONTENTS

Foreword.................................................................................................... 8

Part 1

The Mediterranean deep-sea ecosystems

An overview of their diversity, structure,functioning and anthropogenic impacts

1. Introduction................................ .................................. ...................... 10

2. Deep-sea diversity patterns

2.1. Fa una ............................... .................................. ................................. 11

2.2. S tructure o f dee p-wa ter mediterra nea n c ommunities ....................... 19

3. Functioning of deep-sea Mediterranean food webs

3.1. Overview ................................ ................................. ............................ 22

3.2. Mesos ca le va ria tions in the dyna mics of dee p-sea eco sys tems .... . . . 23

3.3. Huma n a ltera tion o f trophic we bs ................................ ...................... 274. Unique environments of the Mediterranean deep sea

4.1. Cold seeps ......................................................................................... 29

4.2. Brine poo ls ................................. .................................. ...................... 31

4.3. Deep-sea co ra l mounds .............................. .................................. ..... 31

4.4. Seamounts ......................................................................................... 32

5. Anthropogenic impact in the deep Mediterranean

5.1. Fisheries ........ .................................. .................................. ................. 35

5.2. Other a nthropo ge nic threa ts to the dee p-se a Mediterra nea n ............ 36

Part 2

The Mediterranean deep-sea ecosystems

A proposal for their conservation

6. Deep-water habitat protection and fisheries management

6.1. The pa rticula r sta tus of Mediterra nea n w a ters ................................. .. 40

6.2. Interna tiona l policy co ntext ............................... ................................. 40

6.3. A co nservation propo sa l tailored to the Mediterra nea n ..................... 42

References................................ .................................. ............................ 48

Glossary of key ecological concepts.............................. .................... 55

Plates ....................................................................................................... 57


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8

THE M EDITERRANEANDEEP - SEA ECOSYSTEMS. P ART 1 .

The World Summ it on Susta inable Developm ent ( WSSD)( Joha nne sbu rg , 2002 ) h igh l igh te d the ne e d to p r omo teocean conser va t ion , n amely:

1. Maintaining the pr od uctivity and biodiversity of im-portant and vulnerable marine and coasta l a reas(MCPAs), inc luding areas wi th in and beyond na-tional jurisdiction;

2 . Encoura ging the appl ica tion of the ecosystem ap-proach to ocean and f isher ies management by2010 ; a nd

3. Develop ing and facilitating the use of divers e ap-pro aches an d tools , inc luding the establ ishment ofMPAs consistent with international law and basedon sc ient ific inform at ion, toge ther wi th rep resenta-t ive n e tworks b y 2012.

The last Conference of the Parties of the Convention onBiological Diversity (CBD-CoP7, Kuala Lumpur, 2004)agreed to adopt th is approach for the work of theConvent ion on marine and coasta l protec ted areas, andto develop a str ategy to me et this goal.

The CBD acknowledging that: The establi shment andmaintenance of marine and coastal protected are-as that are effecti vely managed, ecologically basedand contribute to a global network of mari ne and

coastal protected areas, building upon national andregional systems, including a range of levels of pro-tection, where human activiti es are managed, par-ti cularly through nati onal legislati on, regional pro-grammes and poli cies, traditi onal and cultural prac-ti ces and international agreements, to maintain thestructure and functioning of the full range of marineand coastal ecosystems, in order to provide benefi tsto both present and future generati ons, s t ressed theimpor tance to ad dress the pr otec t ion of the b iodiversi tybeyond National jurisdiction. It also agrees that there

is an urgent need for in te rna t ional coopera t ion and ac-t ion to improve conserva t ion and susta inable use of b i -

odiversity in marine areas beyond the limits of nationalju r is d ic tio n , in c lu d in g th e e st ab lis h m en t o f fu r th er m a -r ine protec ted areas consistent wi th in te rna t ional law,and based on sc ient i f ic informat ion, inc luding areassuch as seam oun ts , hydrotherm al vents , cold-water cor-

als and other vulnerable ecosystems. The CoP7 invitedthe Part ies to r a ise the ir con cern s regard ing the issue ofconserva t ion and susta inable use of genet ic resourcesof the deep seabed beyond l imits of na tional jur isd ic tion ,and to ident i fy ac tivi ties and pro cesses u nder the ir jur is-diction or control which may have significant adverseimpact on deep seabed ecosystems and spec ies.

This WSSD ca l l has been endorsed by the par t ic ipantsof the Mar ine Theme a t the Vth World Parks Congress, inDurban, South Afr ica (8-17 September 2003) .

The Malaga Workshop on High Seas Protec ted Areas( January 2003 ) s t ressed, in te r a l ia , tha t the leve l of sc i -ent i fic kno wledge of the h igh seas, a nd the deep -sea inpar t icular , needs to be r a ised .

The present document therefore a r ises f rom a jo in t in-itiative between the WWF Mediterranean Programmeand the IUCN Centre for Mediterranean Cooperation, toaddress these issues at a regional level; i t contains, forthe f i rs t t ime, a comprehensive proposa l for conserva-tion firmly based on the scientific information currently

available.Draft versions of th is document were c i rcula ted forconsul ta t ion amongst concerned stakeholders and dis-cussed in several relevant meetings (GFCM-SAC-SCMEE,CIESM). This final version has greatly benefited fromthe feedback gener a ted by th is con sul ta tion pr ocess; theconserva t ion proposa ls inc luded ref lec t a wide consen-sus among sc ient is ts and lega l experts f rom a l l a roundthe Medi te rranean.

Foreword


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ANOVERVIEW OF THEIR DIVERSITY, STRUCTURE, FUNCTIONINGAND ANTHROPOGENIC IMPACTS.

The Eastern and Western Medi te rranean display im-portant geological and biological differences. First, theEastern Mediterranean is geologically more active, be-cause i t i s a contac t zone be tween 3 major tec tonicplates: African, Eura sian an d Ara bian. For this r easo n, itfea tures a wide arr ay of in te rest ing cases of unique b io-c e nose s* , suc h a s mud vo lc a noe s , se a moun t s o r c o ldseeps*. The Western Mediterranean is relatively feature-less in com parison , a l thou gh st i ll not devoid of uniqueenvironments. Biologically, the Western Mediterranean,whilst stil l oligotro ph ic* by Nor th Atlantic stan dar ds, h asrelatively high pr imar y pr od uction, e spec ially in the Gulfof Lions, due to the r iver Rho ne r uno ff and wind m ixing( fig. 2) . The Eastern Medi te rr anean has very low prima-ry production, particularly in the Levantine sea.

Fig. 2. Chlorop hyll a map (Month ly composi te fo r Apr . 2000) p ro-duc ed b y the Inland and Ma rine Waters Unit ( JRC-EC) using SeaWiFSr aw d ata d istrib uted by NASA-GSFC.See colour plate, p. 57.

The cont inenta l she lves, where mo st com mer c ia l fishingactivity is conducted, cover only 30% of the Mediterra-nean sea sur face , whi le the ba thyal dom ain covers 60%and the abyssa l p la in the rem aining 10% ( appr ox.) ( fig.3) . Cont inenta l she lves a re only extensive near the ma-jo r r ive r m o u th s ( th e Rh o n e in th e Gu lf o f Lio n s, th e Nilein the Levant ine sea) , or on the Adria t ic and Tunisiancoasts . A la rge par t of the Medi te rr anean coast has d eep-water beds very near shore, typically a few hours away

by comm ercia l vesse l .

Although fishing for continental shelf resources datesback to anc ient t imes, co mm erc ia l fisher ies in the ba th-ya l dom ain sta r ted on ly in the ear ly decad es of the 20 th century , and have increased in importance since the1950s, especially on the Ligurian, Catalan and Balearicc oa s ts ( Sa rd et al., 2004a) . The development of deep-water com mer c ia l fisher ies was l inked , as in o ther seas,to the developmen t and mo toriza t ion of t rawler vesse ls .Deep-water f isher ies in the Medi te rranean ta rge t red

sh r imps (Aristeus antennatusa nd Aristaeomorphafoliacea) be tw e e n 400 a nd 800 m ( spo ra d ic a l ly dow n

to 1000 m. ) B e ds de e pe r tha n 1000 m c a n be c ons id -ered virg in from the v iewpoint of com mer c ia l exploi ta -tion of living resources.

Throughout the world , commerc ia l f isher ies , basedmo st ly on pr edatory fish , a re suffer ing ser iou s de ple t ion(Myers and Worm, 2003) . Given the s ta te of cont inen-tal shelf fish resources, the fishing industry is directingm or e attention towar ds the p otentially exploitable livingresources of the deep-sea . Waters deeper than 1000 mc ove r a rou nd 6 0 % o f ou r p l a ne t, a nd the ir un ique e c o -systems have been discovered only recent ly (s ince the1970s) . Hydrothermal vents , cold seeps, and cold-wa-ter cora l reefs can be found in dee p waters . Other h abi-ta ts , such as seamounts (Rogers, 1994; Koslow, 1997;Gal i l and Zibrowius, 1998) and submarine canyons(Boui l lon et al., 2000; Gili et al., 1998 ; 2000) , ha ve

been identified as diversity hotspots. Considering theirunique fea tures and low turn-over ra tes , deep-sea eco-systems are h ighly vulnerable to commerc ia l exploi ta -t ion ( Roberts , 200 2) . Global ly, a rou nd 4 0% o f trawlingfishing ground s are now on waters deeper than the con -t inenta l she lf (Roberts , 2002) and many seamount f ish-er ies have been deple ted in shor t per iods of time ( Lacket al., 2 0 0 3 ) .

Fig. 3. Schemat ic represen ta t ion o f the mar ine dep th zones, wi themphasis on concep ts p resen ted in th is document .

2. Deep-sea diversity patterns

2.1. Fauna

2.1.1. Overview

The deep Medi te rranean fauna d isplays a num ber o f char-acter istics that differe ntiate it fro m o ther d eep -sea faunasof the worlds oceans (Bouchet and Taviani , 1992): i )the h igh de gree o f eurybathic* spec ies; i i )a b s e n c e ( o r

low representa t ion) of typica l deep-water groups, suchas macroscopic foraminifera (Xenophyophora) , g lass


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sa l f i sh fauna (Moranta et al., 2003). Fish popula t iondensi t ies a re lower in the Medi te rranean (f ig . 4) , a fea-ture that can be related to the much lower availability oforganic mat te r* on the Medi te rranean seabed in com-parison to the At lant ic , due to the o l igotrophic charac-te r is t ics of the Medi te rranean sea (f ig . 2) . In the sameway, Atlantic fish assemblages are composed of a larg-er number of spec ies than those of the Medi te rranean.This might owe to the recent or ig in of Medi te rraneandeep-sea fauna, after the Messinian salinity event.Comparing the Eastern and Western Medi te rranean ba-sins, the Levantine Sea has a particularly low numberof spec ies and low abundance (Stefanescu et al., 1992 ;Kallianotis et al., 2000) , a nd the a sse mbla ge c ompos i -tion is also q ualitatively differe nt. For instan ce, de ep-seasha rks (Centrophorusspp. , Etmopterus spinax an dHexanchus griseus) a re a mo ng the mos t a bunda n t fi sh

species in Levantine bathyal communities.A charac ter is t ic fea ture of Medi te rranean deep-seamegafauna is the numerica l importance ( in te rms ofa bunda nc e a nd numbe r o f spe c ie s ) o f de c a pod c rus -taceans which, toge ther wi th f ish , a re the dominant

taxa in deep Medi te rranean assemblages. In the deepMe d it e r ra ne a n , de c a pod c rus t a c ea ns a re the dom ina n tinvertebrate taxon, whilst they are of li t t le importancein b iom ass in the Bay of Biscay. Add ition ally, spe cies o ft ropica l or subtropica l or ig in (e .g . Aristeus antenna-

tus,Ari staeomorpha foliacea

,Acanthephyra eximia

)domina te in de e p Me d it e r ra ne a n de c a pod a sse mbla ge s( Ca r t e s , 1993 ) .

Suspension feeders* ( e .g . hexactine l lid spon ges, pennat-u l ids) a r e dom inant in te rms o f invertebra te b iom ass onthe upper and m iddle s lope ( to 1400 m ) in the At lant ic ,whi ls t echinoderms are important a t a l l depths anddom inant on the middle and lower s lope ( Lamp itt et al.,198 6) . Suspension feeder s a r e o f re la tive ly l it tle impo r-tance in the Medi te rr anean, d ue to i t s o logotrop hic wa-ters , and they are impor tant only loca l ly. Prob ably dueto the ir low leve ls of food consu mp tion, c r ustacean d e-c a pods a re mor e impor t a n t i n the de e p Me d it e r ra ne a n( an ol igotroph ic region, Cartes and Sard , 1992) than inthe deep Atlant ic , where ech inoder ms dom inate ( Bil le t tet al., 2 0 0 1 ) .

Megafauna abundance and specie s richness

decreases with depth, but there exists a sec-

ondary peak of biomass between 1000 and

1 5 0 0 m .

Dominant megafaunal groups in the deepMediterranean are fishes and decapod crusta-

ceans

The l evel s o f megafaunal biomass in the deep

Mediterranean are 1 o rder of magnitude lower

than in the Atlantic, at com parable d ep ths, due

to the low p rimary production o f the Mediter-

ranean sea.

Important difference s exist between the east-

ern and the western Mediterranean, both in

species com pos i t ion and abundance

Fig. 4. Compar ison of b iomass by dep th in terval be tween the

Western Medi ter ranean (Balear ic sea) and the At lan t ic (Rockal lt r o u gh ) , b a se d o n M o r a n ta et al. ( 2 0 0 3 ) .

Etmopterus spinax.Drawing by M. Wr tz Ar tesc ienza 1994 .See colour plate, p. 61.


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Box 1. Species composition of megafauna in the Western Mediterranean

Relat ive abu ndance o f decapod crustaceans wi th dep th ,e labora ted f rom d ata from exper imenta l samplings in the western

Medi ter ranean f rom 1988-2001 .

Otter t rawl surveys in the Western Medi te rraneanc a r r i e d ou t be tw e en 19 88 a nd 2001 ( Ste fa ne sc u et al.,1994; Cartes , 1993; Sard et al., 2004b) p rov ide a n

accura te p ic ture of the decapod crustacean and fishspecies composi t ion and biomass d ist r ibut ion withde p th .

Decapod crustaceans

Seventy spec ies of decapo d cr ustaceans h ave bee n r e-po r t e d f rom 200 to 4000 m. F rom the se , 20 a re o fcommercia l in te rest a t present ( inc luding some spe-c ies dwel ling predo minan t ly in sh a l low waters) :

- the red shr imp s: mainly Aristeus antennatus,

bu t locally also Aristaeomorpha foliacea.- o the r r e d sh r imps : Acanthephyraeximia

a nd Acanthephyra pelagica.

- the g lass shr im ps: Pasiphaeasivadoa nd Pasiphaea multi dentata.

- Pandal id shr im ps Plesionikaspp .( d o w n t o 1 0 0 0 m )

Among these species, only 4 reach significant densities(> 0 .1 kg /h in the e xpe r ime n ta l sa mp l ing ge a r ) be -twe e n 1000 a nd 1600 m de p th : Ari steus antennatus,

Geryon longipes, Acanthephyra eximia a nd Munidatenuimana. Below 1600 m the to ta l b iomass of deca-pod c r us t a ce a ns i s ve ry low (< 1 kg /h ) .

The dist r ibut ion of b iomass wi th depth of decapodcrustaceans is shown in the figure be low. There is animpo rtant increa se in b iom ass from 200 to 40 0 m, fo l-lowe d by a sha rp d e c re a se to 1000 m, w he re the de c a -pod bioma ss is prac t ica l ly one tenth of the b iomass a tthe she lf break. A secondary peak of b iomass occursbe tw e e n 1300 a nd 1500 m, though re a c h ing muc hlower leve ls of b iomass. The h igh abundance of Aris-teus antennatusa t a round 1500 m is par t ly responsi-b le for th is seconda ry peak ( Sard et al., 2 0 0 3 b ) .

- the deep water shr im p Parapenaeuslongirostrisa n d Solenocera membranacea( dow n to 400 m on ly)

- t he a nomu ra n c ra bs Munidaspp .

- the Norway lobster Nephrops norvegicus( p re se n t dow n to 700 m on ly) a nd the sp inylobster Palinurus mauri tanicus( 400 m on ly)

- c rabs: Geryon longipes, Paromola cuvieri,Chaceon mediterraneus, a nd Macropipustuberculatus( the la t te r do wn to 600 m o nly) .

Paromola cuvieri.

Drawing b y M. W rtz Ar tesc ienza 197 7 .

See colo ur plate, p. 6 1 .


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2.1.4. Meiofauna

While densi t ies of meiofauna* (or meiobenthos) onthe Medi te rranean cont inenta l she lf a re comparable tothose in o the r o c e a ns ( D a nova ro et al., 2000) , de e p -se ameiobenthos densi t ies a re one order of magni tude low-er in the Medi te rranean than in the northeast At lant ic( Bouchet and Taviani , 199 2; Danovaro et al., 2000 ; a ndespecia l ly be low 1700 m: De Bove et al., 1 9 9 0 ) .

Meiofaunal abundance (exc luding foraminiferans) d i -minishes wi th incr easing depth ( De Bove et al., 1 9 9 0 ) ,a long with environmenta l indica tors of food resources.This pa t te rn is even m ore p ron oun ced in the Eastern ba-s in ( D a nova ro et al.,2000 ) ( fig.5) and the extremely o l-ogotroph ic easte rn Medi te rran ean shows on e of the low-est meiofaunal s tanding stocks in the wor ld ( Tse lepides

a nd La mpa da r iou , 2004 ) .

al., 199 9; 200 0) ; in the Western Medi te rr anean i t i s low-e r ( 2 .5 t ime s) . The c ombina t ion o f low p r ima ry p roduc -t ion and bac ter ia l dominance of secondary product ionin the east is also of significance as it could account forthe low fisheries pro duct ion ( Turley et al., 2 0 0 0 ) .

The rapidly d iminishing meiofaunal abundance is ex-pla ined no t only by the o l igotroph ic na ture of the Medi-te rranean , but a lso b y the r apidi ty of organic m at te r d eg-radat ion in a re la t ive ly warm deep-water environment( De Bove et al., 199 0; Bouch et and Taviani , 199 2) .

Inform at ion on meiobe nthos from tren ches of the abyss-al or h ada l zon es is stil l l imited, but Tselepides an d Lam -pa da r iou ( 2004) show e d tha t me io fa una l a bunda nc e inEastern Medi te rranean deep-sea t renches (wi th depthse xc e e d ing 3750 m) w a s une xpe c te d ly h igh (45 -156

ind /10 c m 2) ; h igher than in surrounding abyssa l p la insa nd c om pa ra b le to m id -s lope ( 1500 m ) de p ths . The a c -cum ula t ion of organic mat te r in deep sea t rench es couldexpla in the h igh meiofaunal abund ance rep orted .

The abundance of meio fauna diminishes with

increasing depth, and is lower in the eastern

Mediterranean than in the wes tern

Local high abundance of meio fauna has been

reported for very deep environments, such asdeep-se a trenches

The combination of low primary production

and bacterial dominance of seco ndary produc-

tion may account for the low fisherie s prod uc-

tion in the eas tern Mediterranean

2.1.5. Endemism

By i ts spec ia l oceanographic s t ruc ture and pa leoecolo-gy, the Medi te rranean Sea has a par t icular fauna com-pared to the nearby Atlantic ocean. Different theoriesabout the or ig in and evolut ion of deep Medi te rraneanfauna have been suggested and documented. Examplesare the Tethys hypothesis, which postulates that the ori-g in of some Medi te rran ean end emism s are faunal re l ic tssurviving the Messin ian cr is is (Prs, 1985) , and thepseudopopula t ion hypothesis by Bouchet and Taviani( 1992) , e xp la in ing the oc c u r re nc e o f some spe c ie s inthe Medi te rranean not as reproducing popula t ions, butas maintained by the periodical influx of larvae trough

In genera l , meiofaunal abun dance is dom inated by nem -atodes, wi th important f rac t ions of harpac t icoid cope-pods and polychaetes. In the Western Medi te rranean( Gulf of Lions an d Cata lan Sea) , the m eiofauna is dom i-na ted by nematodes (92.4%). In the Cata lan Sea meio-

faunal densi ty var ied seasonal ly from 296 (Septem-be r ) t o 746 (Ma rc h ) ind c m-2 (C a r t e s et al., 2 0 0 2 )a t a round 1200 m depth . Nematode b iodiversi ty be low500 m in the Eastern Medi te rranean is lower than inother e qual ly deep sedimen ts worldwide , and even low-er than with in a Medi te rr anean can yon a t 1500 m depth(D a nova ro et al., 1 9 9 9 ) .

Below 500 m depth in the Eastern Medi te rranean, thecontr ibut ion of bac ter ia to organic mat te r degradat ionis s ignificant ( bac ter ia r epre sent 35 .8% o f the l iving b io-

mass, Danovaro et al., 1995) a nd the ba c te r ia l to m e io -faunal b iom ass ra t io is very h igh ( 20 t imes, Danovaro et

Fig. 5. Meiofaunal abun dance b y dep th , combin ing datafrom De Bove et al. ( 1 9 9 0 ) , Da n o va r o et al. ( 1 9 9 9 ; 2 0 0 0 ) .


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Lepidion lepidion (R isso , 1810)

Lota lepidionRisso,Moustella de Fount Stocofie,V. Fossat, 1879 .Coll. Musum dHistoire naturellede Nice.See colour plate, p. 58.

the Straits of Gibraltar. Most components of the Mediter-ra ne a n de e p -w a te r f a una (de e pe r tha n ca. 2 0 0 m ) b a -sically derive from impoverished communities of Atlan-

tic origin.

I t has been est imated tha t a round 26.6% of the to ta lMedi te rranean marine fauna (4238 spec ies: Fredj et al.,1992) a re endemic . Though no similar overa l l ba lanc-es exist specifically for the deep-sea fauna, the percent-age of endemisms is h igher than the mean above c i tedfor some taxa ( e.g., 49 .2% Amphipoda , Ruffo , 1998) .For some taxa , even end emic generac a n be found ( e.g.,in decapod crustaceans: Levantocaris, Zariquieyon) ,whi le in o ther taxa with a h igher number of endemicspe c ie s ( a m ph ipods) , no e nde mic gene ra a re r e po r t e d .As expla ined above for Amphipoda , the proport ion ofendemisms by taxon is probably closely related with lifest ra tegies. For example , no endemic cephalopods arerep orted in the deep Medi te rr anean ( R. Vi llanueva , pers .com m.) , prob ably due to the possession of free-pe lagicla rvae d ist r ibuted in the ent i re water colum n.

Tor tone se (1985) r e po r t e d 6 e nde mic f i she s be low1 0 0 0 m : Bathypterois mediterraneus, Paralepis speci-osa, Rhynchogadus hepati cus, Eretmophorus kleinen-bergi, Lepidion lepidion a nd Paralipari s leptochirus.

Only two of these sp ec ies a re found both in the easte rnand western Medi te rranean.

Among decapod crustaceans, Levantocaris hornun-gae (Gal i l and Clark , 1993) , and the la rge crabs Cha-ceon mediterraneus(Manning and Hol thuis , 1989;

Ca r t e s , 1993 ) , a nd Zariquieyon inflatus( Ma nn ing a ndHolthuis , 1989) a re endemic . Only 2 of the 28 spec iesof decapods col lec ted in the Cata lan Sea be tween 862-2265 m w e re e nde mic (C a r te s , 1993 ) . 2 o f t he 3 e nde m-ic decapods are found both in the easte rn and westernBasins, while Z. inflatushas b een co l lec ted only in thewestern Medi te rranean.

Tor tone se (19 85) r e po r t e d 4 e nde mic e ch inode rms be -low 200 m, 1 d omina n t (Leptometra phalangium) a n d3 ra re spe c ie s ( Prototrochus meri dionalis, Irpa lud-

wigi,Hedningia mediterranea

) .

In the case of macrofauna , a l though the depth d ist r ibu-t ion of endemisms is more or less acknowledged, i t i shard ly kno wn i f these endem isms are uniform ly distr ib-uted a long a l l deep Medi te rranean Basins. In the caseo f pe ra c a r id c ru s t a c e a ns , be tw e e n 552 a nd 1808 m inthe Cata lano-Balear ic Basin , Cartes and Sorbe (1995)reported 3 endemic Mysidacea of the to ta l of 16 spe-c ies col lec ted , 4 of the 32 spec ies of Cumacea (Cartesand Sorbe , 19 96) , and 26 o f the 82 spec ies of Amp hipo-da (Cartes and Sorbe , 1999) . Therefore , 25 .4% of ba th-

yal peracarids in the Catalano-Balearic Basin can beconsidered as endemics. Previously , a s imilar propor-


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t ion (24.2% of the 99 spec ies col lec ted) of ba thyal-su-prabenthic Peracarids were c i ted as Medi te rranean en-demics in the same area (reca lcula ted from Cartes andSorbe , 1993 ) a t s imi l a r de p ths ( f rom 389 to 1859 m) .In the Algerian Basin , a t depths be tween 249 and1622 m, the pe rc e n ta ge o f e nde misms a mong sup ra be n -thic Perac ar ids was slightly lower tha n in the Catalan Sea( 18.2% : ca lcula ted from Cartes et al., 2 0 0 3 ) .

The num ber of endemism s is low, par t icular ly in the deepbathyal domain and be low 250 0-300 0 m. This bou ndar yhas been suggested by some authors (Prs, 1985; Bel-lan-Sant in i , 1990) as the upper l imit of d ist r ibut ion ofthe t rue abyssa l fauna . However , the number of Medi-t e r ra ne a n de e p -se a e nde misms c ou ld ha ve be e n ove r -estimated simply by differences in sampling between thede e p Me d i te r ra ne a n a nd su r round ing b ioge ogra ph ic a r -

e a s ; some de e p a mph ipods (e .g . Rhachotropis caeca,Lepechinella manco, o r Pseudoti ron bouvieri) , c a t a -logued as endemic Medi te rranean spec ies, have in re -cent years been found in the Bay of Biscay and the Can-tabric Sea ( Bachele t et al., 2 0 0 3 ) .

Converse ly , new sampling programmes are increasing-ly repo rt ing new endem ic taxa in the deep Medi te rrane-an, and the faunal composi t ion of deep-sea communi-ties is far from being completely recognized , especiallyfor smal l faunal grou ps.

The number and type of endemisms in the

deep Mediterranean are the result of i ts par-

ticular paleoe cology. They sho uld be an impo r-

tant criterion in defining future MPAs in deep

Mediterranean eco systems .

Some faunis t ic groups such as amphipods

present high rates o f endemism in the deep

Mediterranean.

The number of endemic species among meg-

afaunal taxa in the deep Mediterranean are 6for fishes , 4 for decapod crustaceans and 4 for

echinoderms.

2.2. Structure of deep-waterMediterranean communities

2.2.1. Continental slope

Two main b iocenoses ( fac ies) in the ba thyal Medi-

te rranean have c lassica l ly been defined (Prs, 1985):i ) sof t -bot tom communit ies; i i) h a r d - b o t t o m c o m m u -

ni t ies . Prs and Picard (1964) establ ished the t ransi -t ion be tween the c i rca l i ttora l and ba thyal dom ains in theMe d it e r ra ne a n a t a round 180 -200 m de p th . D e pe nd ingon the na ture of the sediment (which depends in turnon fac tors such as hydrodynamism and mainland inf lu-e nc e ) , t h re e ho r i zons w e re e s t a b li she d by P r s ( 1985)in the sof t -bot tom communit ies: the upper , middle andlower s lope horizons. The upp er s lope ho rizon is a tran-si t ion zone be tween the coasta l zone and ba thyal do-mains, com prising a la rge share o f eurybathic form s andextending to 400-500 m deep. The sea pen Funiculi-na quadrangularisa nd the c ru s t a c e a ns Parapenaeuslongirostrisa nd Nephrops norvegicusa re c ha ra c te r -is tic spec ies of th is ho rizon. The midd le s lope ho rizon,charac ter ized by f i rmer and more compact muds, i s thezone where most taxa achieve maximum diversi ty . Forf ish and decapods, in the NW Mediterranean, th is ho-

r izon extends to a depth of 1200-1400 m. The cnidar-ian Isidella elongata, the c rustaceans Aristeus anten-

natusa nd Aristaeomorpha foliacea a re charac ter is t icexamples. The lower s lope horizon is not so wel l s tud-ied , but some c harac ter is tic megafaunal spec ies can b el is ted: decapods, such as Stereomastis sculpta, Acan-

thephyra eximi a a nd Nematocarcinus exi li s, and fish-es, such as Bathypterois mediterraneus, Alepochepha-lus rostratus, Lepidion lepidion a nd Coryphaenoidesguentheri. H a rd bo t toms a r e r e p re se n te d be low 300 ma nd dow n to 800 -1000 m, in a re a s w he re h igh hyd ro -dynamism prec ludes sedimenta t ion and exposes barerock . In the nor thern Ionian sea ( Santa Maria d i Leuca)a unique b iocenose of whi te cora ls has been reportedfrom 450-1100 m de p th (Ma s t ro to ta ro et al. 2002 ; Tu r -si et al. 200 4) . Live co lonies of Madrepora oculataa ndLophelia pertusawere found , wi th a r ich epibiont fauna .

These spec ies occur e lsewhere in the Medi te rranean asfossi ls or subfossi ls (Pr s, 1985 ) , see Box 6 .

Ari steus antennatus

Albert Ier Pr ince d e Monaco . Camp. sc ien t . Pnids p l . I I I .EL. Bouvier del, M. Bor rel pin x.Col l . Oceanograph ic Museum , Monaco .See colour plate, p. 59.


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In the marine environ men t , depth is assumed as the ma-jo r fo r c in g fac to r s tr u c tu r in g c o m m u n iti e s: sp ec ie s as-semblages and communit ies show more var iabi l i ty ver-tically, as a function of increasing depth, than over thehorizonta l d imension (Rowe and Menzies, 1969; Hae-d r i c h

et al.,1975; 1980; Hecker , 1990a; Cartes and

Sard , 19 93; Stefanescu et al., 1994). This observa t ionsuggested the idea of the zonat ion phenomenon: depthbands of h igh faunal homogenei ty separa ted by bound-aries of faunal renewal. Species are usually distributedalong ecologica l gradients in a be l l -shaped curve , andthis is also obse rved with divers ity. Ecological theor y andobser va t ions show tha t spec ies a re d ist r ibuted a long en -vironmenta l gradients (see e .g . te r Braak and Prent ice ,198 8) , having a d i ffe ren t habitat ampli tude o r centreof gravityin the i r d is t r ibut ion ( Stefanescu et al., 1994 ,for a Medi te rranean deep-sea example) . Along a depth

g ra d ie n t , spe c ie s show a l so a m in imum a nd m a x imumdepth of occurrence , wi th an in termedia te depth , theDepth of Opt imal Abun dance ( DOA) , where the ir densi-ty is the highe st. Spec ies m ay find b etter living con ditions,i .e . trop hic req uirem ents , a t th is DOA, as a con sequen ceof an adap t ive success to the environ men t . In deep-Med-i te rr anean fish assemb lages, for instance , m ost fish spe-c ies showed an incr ease in the ir t rop hic d iversi ty* asso-c ia ted with the DOA ( Carr assn a nd Cartes , 2002) .

Boundaries of faunal change have been descr ibed indeep ecosystems, both a t ba thyal and abyssa l depths.

Most deep-Medi te rranean spec ies have an eurybath-ic d ist r ibut ion . This is probably due to the h igh ther-mal (13-13.5C in the western basin ; 14-14.8 C in theeastern basin) and sa l ine (38.5-38.6 PSU) stabi l i ty ofthe water mass be low 150 m in the deep Medi te rranean( H opk ins , 1985 ) . P r s ( 1985) a l r e a dy p ropo se d a pa t-te rn of change with depth for deep Medi te rranean fau-na. Although with important local variations, a faunalrenewal be l t be tween the upper and middle par t of thes lope a pp e a rs r e c u r re n t ly be tw e e n 300 a nd 7 00 m fo rmegafaunal assemblages, both in oceanic regions and in

the Medi te rranean, and in the deep Cata lan Sea (north-western Medi te rranean) a t ca.500 m de p th ( Abe l l etal., 198 8; Cartes et al., 1994) . A se c ond , de e pe r , bound-a ry be twe e n 1000 a nd 1400 m h a s a lso be e n re po r t e din deep sea ecosystems (Haedrich et al., 1980 ; W e nne rand Boesch, 1979; Cartes and Sard , 1993) and, in thedeep Medi te rranean, i t separa tes the middle and low-er s lope assemblages (Prs, 1985; Cartes and Sard ,1993) . Due to the par t icular pa leoecolgica l condi t ionsof Medi te rranean bio ta , and the lack of a thermal gra-dient be low 150 m, the boundary be tween ba thyal and

abyssal depths h as no t been clear ly identified. The abyss-a l communit ies in the deep Medi te rranean are extreme-

ly impoverished in spec ies, and boundaries a re maskedby the eurybathic charac ter of deep Medi te rranean spe-c ies; some authors even q uest ion the existence of a t ru lyabyssa l fauna in the deep Medi te rranean (Prs, 1985) .

Each dep th assem blage is charac ter ized by its own leve ls

of b iomass, pr odu ct ion and faunal d iversi ty. In the d eep-ba thyal Medi te rranean, a decrease in spec ies r ichnessbelow 1300 m has been reported to occur in d i ffe renttaxa ( e .g . in amph ipods, Cartes and Sorbe , 199 9) . Moststudies available are d escr iptive in natur e, with lit tle datat ry ing to re la te changes in faunal assemblages wi th en-vironm enta l var iables tha t could expla in p ossib le zona-t ion pa t te rns. Therefore , possib le causes for spec ies d is-tribution are far from being fully established. Some dif-fe rences in zonat ion pa t te rns have been found depend-ing on the t rophic leve l of each taxon. Zonat ion ra tes

regularly increase with trophic level (Rex, 1977; Cartesand Carrassn, 2004) , and, in the western Medi te rra-nean, lower ra tes of zonat ion were found in peracarids( be longing to a low t rophic leve l) co mp ared to f ish anddecapods. Trophic and bio logica l causes may expla in ,in a thermal ly s table environment , pa t te rns of d ist r ibu-t ion an d zonat ion of deep-sea Medi te rr anean spec ies.

The ba thymetr ic loca t ion of bou ndar ies of faunal r enew-al a lso shows loca l var ia t ions, acco mp anied by changesin the loca t ion of peaks of b iom ass wi th d epth . Concer n-ing faunal zonat ion , mid and low bathyal communit ies

(w he re the domina n t t a xa a re f i sh , de c a pods a nd pe r -a c a r id s ) a re d i s tr ibu ted de e pe r in more e u t roph ic a re -as ( the con t inenta l s ide of the Cata lan Sea) than in theinsular a rea of the SW Balear ic Is lands, a more o l igo-t rophic zone ( Cartes et al., 2004). The d isplacement ofthe de p th w he re bounda r i e s a re loc a te d se e ms a c onse -quen ce of var ia t ions in t ro phic fac tors ( e .g . organic mat-te r enrichment by r iver d ischarges) . Thus, wi th in thesame community , th is t rend is most evident among spe-cies situated at the lowest trophic levels species witha higher sensitivity to changes in the quality of primary

sou rc e s o f food ( p r ima ry p roduc t ion a nd d e t r it u s ) .

2.2.2. Submarine canyons

A factor inducing local changes in zonation is the oc-currence of ac t ive submarine canyons (f ig . 6) , whichpresent a physical discontinuity of the continental slope.Act ive sub mar ine canyons ar e imp ortant pa thways chan-neling advective inputs of mainland origin, such as riv-er outf low, media ted by nepheloid* layers (Durr ieu deMa drn et al., 1999; Puig et al., 2001). Canyons have

a h ighe r o rga n ic c a rbon c on te n t tha n su r r ound ing a re -as (Busca i l and Germain , 1997) , and preferent ia l t rans-


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0

2000 m

Fig. 6. Topograph y of a submar ine can yon .Credits: GRC Geocinci es Marines (Uni versitat de Barcelona)

and RMRInsti tut de Cincies del Mar (CSIC), modifi ed.See colo ur p la tes , p . 63 -64 .

port of mater ia l wi th in the canyons compared with ad-ja ce n t o p en sl o p e ar ea s h as b e en d o cu m en te d ( Mo n a coet al., 199 9) . Local sedim entary events of h igh in tensi -ty have been rep orted o n the con t inenta l s lope , d isplac-ing la rge masses of par t icula te mater ia l over consider-able d istances. These phenomena are the or ig in of d is-turbance* a t smal l t ime and space sca les (Crassous etal., 1991). Concerning the response by organisms, h ighma c ro - a nd me io fa una l b ioma ss ha s be e n re po r t e d in

canyons ( Cartes , 1998a) , and they are a lso impor tant tomegafaunal commerc ia l f isher ies (e .g . red shr imp f ish-er ies in the v ic in i ty of western Medi te rranean subma-r ine can yons: Sard et al., 199 4; Stefanescu et al., 1994 ;presence of Aristeus antennatusa t sha l low depths inthe canyons of the Nile delta, B. Galil , pers. comm.).In the de e p Me d i t e r ra ne a n , subma r ine c a nyons a reimportant for ecosystem st ruc ture and funct ioning be-cause :

1) Canyons can ac t as a sourc e and reser voir of endem icspecies. A number of highly specific populations of Hy-

dromedusae , col lec ted by sediment t raps, have been re-cent ly descr ibed from subm arine canyons in the westernMedi te rr anean ( Gili et al., 1998; 2000) , wi th d i ffe rentspec ies foun d in each c anyon, separa ted by less than1 0 0 k m .

2) canyons can ac t as a pa thway for l i t tora l spec ies tocolonize the deep water , when they are carr ied downby advective inputs (colonization of bathyal depths byspecies l iving in har bou rs in the Toulon c anyon: Storaet al., 1999; l i t tora l spec ies found be low 1000 m, e .g .

Psammogammarus caecusin the Catalan Sea: Cartes

a nd So rbe , 1999 ) .

3) migra tory micronektonic* crustaceans (hyperi ids,euphausi ids) tend to accumula te in the canyon head(Macquart -Moul in and Patr i t i , 1996) . A biomass accu-mula t ion o f sup ra be n thos ( Ca r t e s , 1998a ) a nd de c a podcrustaceans (Cartes et al., 1993) ha s a l so be e n re po r t -ed , wi th mo re o r less evident seasonal f luc tua t ions.

4) Species inhabiting canyons or their vicinity (e.g. there d sh r imp Aristeus antennatus, Cartes , 199 4; Sard etal., 1994) show te mpor a l c ha nge s in a bunda n c e , p rob -

ably as a conseq uence of the se asonal ly-varying accu mu -la tion of food resou rces in can yons. Higher recr ui tmentof macro- and megafaunal spec ies in to or in the v ic in-i ty of canyons has a lso been documented (Sard et al.,199 4; Stefanescu et al., 1994 ; Ca r t e s a nd So rbe , 1999 ) .

5) By changing the vort ic ity of under water curr ents , can-yons are respo nsible for loca l upwel ling , resul t ing in anenrichment of the water column and pe lagic systems.Important concentra t ions of smal l pe lagic f ish , ce ta-ceans and birds a re observed in the epipe lagic* layerin w a te r s ne a r subma r ine c a nyons (Pa lome ra , 1992 ;

Abell et al., 2 0 0 3 ) .

In decapod crustacean communit ies , however , spec iescomposi t ion was similar be tween canyons and sur-rounding areas, and only some secondary spec ies werepreferent ia lly d istr ibuted , or mo re ab und ant , in canyons(e .g . Ligur ensiferus,Plesionika edwardsi: Cartes etal., 1 9 9 4 ) .

In conclusion, the b io logica l d i ffe rences be tween can-yons and surrounding areas resul t f rom differences inbiomass, ra ther than the establ ishment of d ist inc t com-

mu ni t ies or spec ies ( exc luding perh aps the endem ic je l -lyfish spec ies re po rted by Gili et al., 1 9 9 8 ; 2 0 0 0 ) , p r o b -ably as a consequence of the h igh hydrodynamism ofthese type of environ men ts.

Physeter catodon.

Drawing b y M. Wrtz. Ar tesc ienza .

See colour plate, p. 61.


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3. Functioning

of deep-sea Mediterraneanfood webs

3.1. Overview

Early investigations p ointed to a high s tability of bathyalecosystems, regarding both the ir s t ruc ture and dynam-ics (Grassle , 1977) . Stabi l i ty was a lso assumed a t sea-sonal and in terannual t ime sca les. This v iew, however ,has progressive ly changed in recent decades wi th theincreasing evidence of aspec ts such as the seasonal in-flux of phytodetr i tus to deep sea environ men ts (Heck er ,1990b) a nd the non -c on tinuous re p roduc t ion o r pe a ksin the recrui tment reported for deep sea spec ies ( s e eBox 2) . Changes have a lso been reported on an in ter-

annual sca le (e .g . over a per iod of 10 yr in PorcupineAbyssal Plain: Billett et al., 2001 o r i n hyd ro the rma lvents: Lutz and Haymon, 1994) , and i t has a lso beensuggested tha t c l imate change is influencing the q uant i -ty and qual i ty of food reach ing deep-sea Med i te rr aneanecosystems (Danovaro et al., 2 0 0 1 ) .

Global ly, the Medi te rrane an sea is considered an o l igo-t rophic region. Based on sa te l l i te imagery da ta (SeaW-iFS, f ig . 2) , the mean annual surface pr imary produc-tion, as indicated by the Chlorophyll-a pigment, rangesbe twe e n 1 a nd 2 m g /m 3/ yr in th e m o st p r o d u c tive a r e -

as, such as the Gulf of Lions or the Alboran Sea, and 0.1-0 .2 mg /m 3/ yr in th e SW Ba le ar ic Is la n d s, 0 .0 5 m g/ m 3/ yrin the Tyrrhenian sea , and only 0 .02-0 .03 mg/m 3/ yr inthe m ost o l igotroph ic a reas in the Levant ine sea , to thesouth o f Cre te and Cypru s. The pr im ary prod uct ion, theflux of par t ic les a long the water co lumn ( to ta l par t ic leflux be tween 32 .9 and 8 .1 g /m 2/ yr a t 8 0 an d 1 0 0 0 m , r e -spectively: Miquel et al., 1994 in the Ligurian Sea) andthe concentra t ion of ( to ta l or labi le ) organic mat te r ondeep-sea bot toms fo l low a seasonal pa t te rn wi th peakstha t seem to be coupled with the spr ing peak of pr ima-

ry product ion (Carpine , 1970; Danovaro et al., 1999 ;Cartes et al., 2002). Surface pr imary product ion of tenpeaks a round Apri l (Cartes et al., 2002) , w h i l e o rga n -ic mat te r f lux is a t a maximum in June (Miquel et al.,1994) in the Ligurian sea . For organics in deep sedi-men ts , there is only d iscont inuous da ta ava ilable ( Carteset al., 2002) . Pe a ks se e m to oc c u r a l so a round June(Me de rna c h , 2000 ; C a r t e s et al., 2002) . P r ima ry p ro -duct ion , phytoplankton pigment conce ntra t ion and f luxof particles are, for instance, lower in the Catalan sea(NW Mediterranean) than in the Bay of Biscay (NE At-

lant ic ) , loca ted a t s imilar la t itude ( Busca i l et al., 1990 ,summarized by Cartes et al., 2001b) . Pa r t i c u la t e o r -

ganic mat te r (POM) in deep bot toms, a l though varyingdepending on loca l condi t ions, i s a lso low in the deepMedi te rr anean, p ar t icular ly in the Eastern Basin ( Dano-varo et al., 1 9 9 9 ) .

Danovaro et al. (1999) r e po r t e d tha t ma ss f luxe s a t

equal depths a re up to two orders of magni tude h igh-er in the Western Medi te rranean (Gulf of Lions) thanin the Eastern Medi te rranean (Cre tan sea) . 10% of thecarb on in surface waters is expor ted to 100 0 m de pth inthe Western Medi te rranean, but only 2-3% in the East-ern Medi te rr anean , whi ls t bac ter ia l densi t ies a re 4 t imeshigher in the form er than in the la tte r . The sam e author salso reported different efficiencies in the transfer of or-ganic mat te r to the deep sea be tween the west and theeast 10% and 1% respec t ive ly . This has profound im-pl ica tions in te rm s of ben tho-pe lagic co upl ing.

The high thermal s tabi l i ty of the deep Medi te rrane-an probably contr ibutes to a rapid degradat ion of thePOM reaching the deep bot toms, resu l ting in po or q ual-i ty (or re frac tory) food for the benthos. In the absenceof changes in abiot ic fac tors such as temper a ture , foodavailability and local pr od uctivity regim es m ight explainimpo rtant b io logica l fea tures ( e .g . spec ies comp osi tionand size d ist r ibut ion) of the Medi te rranean fauna . Thetrophic level of species and the dietary diversity explainpat te rns of d ist r ibut ion overlap ( i .e . possib le compe-tence be tween spec ies) , and the depth range occupiedby Me d i te r ra ne a n top p re da to r s b e low 1000 m ( Ca r t e sand Carrassn, 2004) . In the context of a genera l ly o l -igotrophic region, such as the deep Medi te rranean, i ti s of par t icular s ignificance to u nder stand the funct ion-ing of a reas of comp ara t ive ly h igher pr odu ct ion , su ch ascanyons and upwel l ing regions.

With the except ion of some extreme en vironm ents ( coldseeps) , most deep ecosystems in the Medite rranean area l loc thonous ( i .e . , they depend on POM orig ina t ing inthe phot ic zone or of te rr igenous or ig in) . At present ,

mo st of the inform at ion o n the s t ruc ture and funct ioningof t rophic webs concerns megafauna dwel l ing on mud-dy bot tom s. Deta i led informat ion on d ie ts and r esour cepart i t ioning of f ish and decapod crustaceans ava i lablefrom the Cata lano-Balear ic Basin (western Medi te rra-nean) indica tes:

1) Die ts a r e gener a l ly h ighly d iversi fied ( Shann on indexreaching 5 .3 b i ts in the d ie t of the red shr imp Aristeusantennatus: Cartes , 1994 ) ;

2) Fish and decapods are organized in three d i ffe rent

t rophic leve ls , as reported from isotopic ana lyses (Pol-un in et al., 2 0 0 1 ) ;


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Box 2. Reproductive strategies of deep-water species:recruitment patterns in productivity hotspots

Althou gh m ost s tudies were o r ig ina l ly focused on com -merc ia l spec ies of f ish and decapod crustaceans (e .g .

the re d sh r imp Aristeus antennatus) , the re i s now de -ta iled inform at ion on the b io logica l cyc les of a num berof deep Medi te rranean spec ies. Suprabenthic peracar-id c rustaceans (Cartes and Sorbe , 1999; Cartes et al.,2001b), and non-commercia l , though ecologica l lyimportant , f i sh and decapods have been the topic ofthese s tudies ( e .g . Macrouridae : Massut et al., 1995 ;DOnghia et al., 199 9; Pandal idae : Com pany and Sard ,2000; Pasiphaeidae : Company et al., 2001; Polycheli-dae : Abel l and Cartes , 1992) . Both cont inuous andnon-cont inuous reproduct ive pa t te rns have been doc-

umented, wi th some t rend towards seasonal i ty , or an-nual r est r ic ted per iods of maturi ty, in m id-slope dwel l-ing spec ies wi th increasing depth , both among Cuma-c e a ( Ca r t e s a nd So rbe , 1996 ) , a nd Pa nda l ida e ( Com-pany and Sard , 2000) . Biologica l t rends wi th depthhave a lso bee n studied in the last decade ( Stefanescuet al., 1992 ; Sa rd a nd Ca r t e s, 1993 ) . Some domina n tspec ies fo llow a b igger-deeper and smal le r-sha l lowert re nd ( e .g. Phycis blennoides, Mora moro,Plesioni-ka martia) preferent ia l ly on the upper and middleslope , whi le some show a smal le r-deeper t rend (e .g .

Aristeus antennatus) , on the lowe r s lope , a nd some

species do not show any significant size-related trendwith depth at all (Morales-Nin et al., 2 0 0 3 ) . P r o b a -

bly the depth of recrui tment and reproduct ive aggre-ga t ions by deep-water spec ies depend on a n um ber o fphysica l and t rophic fac tors which may vary be tweenspecies. A l ink has been suggested , for example , be-tween phytodetr i tus* deposi t ion and recrui tmentfor smal l suprabenthic spec ies (Cartes et al., 2001a ,200 1b) . In megafauna , a l ink be tween recru i tmen t andthe occur rence o f neph eloid layers ( Puig et al., 2 0 0 1 )ha s be e n sho w n fo r p a nda l id sh r imps .

Puig et al. (2001) showed tha t the la rva l and recrui t -

ment processes of three deep-water pandal id shr imps( g e n u s Plesionika) w e re re l a t e d to ne phe lo id de -tachments a t the cont inenta l margins, a long a narrowbathymetr ic r ange o f ca. 400 m depth . The existenceof a nepheloid layer is the result of the overall watermass c i rcula t ion in the NW Mediterranean area (fron-ta l s t ruc ture) . Fronta l s t ruc tures loca ted a t a round400 m de p th a re w ide sp re a d in the oc e a ns w or ldw ide(Puig et al., 200 1) and su ggest the existence of a pref-eren t ia l recru i tmen t habi ta t for som e con t inenta l s lopespec ies.

/


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Another impor tant aspec t of the p opu la tion dynamicsof deep-water spec ies is the presence of seasonal re -pro duct ion pe aks, desp i te the ap par ent s tabi li ty of ec-ologica l cond i tions in the d eep se a . A study on the du -ra t ion of the reproduct ive per iods of 17 deep-water

decapod crustaceans (some of them dwel l ing be low1000 m) show e d tha t the i r r e p rod uc t ive pe r iods w e remore c lear ly seasonal than those of spec ies dwel l ing

a long the she lf and upper-slope cont inenta l margins(C ompa ny et al., 2003) . The shorter reproduct ive pe-r iods shown by deep-sea dwel l ing spec ies (Fishe lsonand Galil , 2001; Company et al., 2003) a re a n a spe c tof their l ife histor ies that might affect their co m m erc ial

exploi ta t ion . The r epro duct ive ou tput of deep-sea spe-c ies could be compromised i f any exploi ta t ion is un-dertaken during the ir short reproduct ive per iod.

Box 3. Diversity, biodiversity and species richness

Graphical syn thesis o f the th ree fo rm s to und erstand the term biodiversity.

Diversity

2385 individuals116 kilogrammes

3 species

Boops boops1195 individuals60 kilogrammes

Diplodus annularis760 individuals30 kilogrammes

Pagellus acarne430 individuals26 kilogrammes

Diversity

Diversity

refers to the absolute number of speciespresent, or any other measurement

that incorporates the number of speciesas well as its relati veabundance(Norse et al., 1 9 8 0 inWil son, 19 88) .

Biodiversity

1000 m in depth

Rationale

As discussed earlier, notwithstanding the potential ef-fec ts of o ther an throp ogenic per turb a t ions, such as g lo-ba l warm ing and pol lu t ion , fish ing const i tu tes the m ostimmedia te , foreseeable short - te rm threa t to Medi te rra-nean deep-sea ecosystems. As happens throughout the

world, the progressive depletion of traditional fishinggrounds, toge ther wi th technologica l c reep , i s push-


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A PROPOSALFO R THEIR CONSERVATION

ing fishing activities towards offshore areas, on muchde e pe r g rounds . Me d ium-sc a le bo t tom t ra wle r s ( somewith a desk length of bare ly 15 m) ta rge t ing deep-seashrimp s a l ready reach fish ing groun ds a t a depth of 800m in some Me d it e r ra ne a n a re a s on a r e gu la r ba s i s (de -pe nd ing on the se a son ) , a nd a re inc re a s ing ly a pp roa c h -ing the 1000 m isobath , par t icular ly when sh rimp avai l-ability is low. Ho wever, suc h fishery has no t yet affectedthose important f ish communit ies occurr ing a t a deptho f a round 100 0-1500 m.

The sc ient i f ic basis support ing th is measure has beenextensive ly d iscussed ear l ie r in th is document , on thebasis of spec if ic Medi te rranean studies. Indeed, deep-sea b io logica l com mu nit ies h ave an in t r insic h igher vul-nerabi l i ty to externa l per turba t ions (which may be ex-treme in the case of particularly impacting fishing sys-tems, such as bottom trawling). Also, the few fish re-sou rc e s a bunda n t e nough to suppor t c omme rc ia l f i sh -er ies there in the Medi te rranean are current ly non-mar-ke table spec ies. Further mo re , any eventua l exploi ta t ionof these p opu la tions would lead to a r apid dep le tion ofthe s tocks, would st ron gly d isrup t the par t icular t roph icwebs there , and would cause a deep imp act on the s t ruc-ture and funct ioning of Medi te rranean deep-sea eco sys-tems, which have started being scientifically exploredat a significant scale only in recent decades. In addi-t ion , as sc ient i fic s tudies point o ut , a fur ther expansion

of fisher ies down the ba thymetr ic range would threa tenthe susta inabi li ty of curren t deep-sea fisher ies in the r e -gion, namely those of deep-water a r is te id shr imps, forwhich deeper grounds current ly p lay the ro le of na tu-ra l re fuges and nursery grounds for the juveni le popu-lation fraction.

Implementation

I t i s important to point out tha t l imi t ing the maximumdepth in the Medi te rranean suscept ib le to exploi ta t ion

by f ish ing to the isobath of 1000 m would be a precau-t ionar y measure suppo rted b y soun d sc ient i fic evidence ,in the l ine r ecom men ded by Decision VII /5 adop ted byCBD COP-7.

Furthermore , the proposed deep-sea f ish ing l imita t ionshould be considered more a rest r ic t ion on potent ia lf ish ing development than a t rue f ish ing ban, s ince noregular f isher ies a re taking place a t those depths a tprese nt . In th is sense , i t is impo rtant tha t s takeho ldersful ly understand the ra t iona le support ing th is measure

that clearly benefits the sustainability of fishing activity a nd suppo r t t he p roposa l a s w e ll .

Accord ing to the par t icular lega l s ta tus of Medi te rr aneanwaters d iscussed abo ve , i t appear s tha t the ado pt ion andimplemen ta tion of th is measu re shou ld be done througha binding r esolut ion , a ime d b oth a t the do mest ic leve l ofcoasta l s ta tes ( inc luding the European Union throughthe new regula t ion on Medi te rranean f isher ies manage-m ent) , and a lso at the level of the re levant Regional Fish-eries Management Organization, that is the General Fish-er ies Com mission for the Medi te rranea n.

6.3.3. Conserving deep sea ecosystems

in the Mediterranean:

Element 2.

Representative network of deep-sea

protected areas

Rationale

As descr ibed in de ta i l in th is repo rt , there a re a n um berof specific habitats with particular biodiversity impor-tance in the Medi te rranean deep-sea . These inc lude sub-mar ine canyons, cold seeps assoc ia ted to mud volcanoes(harbouring chemosynthe t ic communit ies) , cold watercora l r eefs , seamo unts and br ine p ools . Also , there isincreasing consensus on the importance of the abyssa lareas curr ent ly poo rly s tudied to b iodiversi ty in theregion. Based on our present knowledge , the loca t ionsof these habitats are represented in fig. 9, but this figureshould not exc lude protec t ion of o ther unique si tes ofsimilar charac ter is t ics tha t we expect might be d iscov-ered in the fu ture .

The implementa t ion of a genera l l imi ta t ion on deep-sea f isher ies be low the isobath of 1000 m as proposedabove would e l iminate the r isk of a profound a nthrop icimpact due to the la rge-sca le removal of b iomass fromthe ecosystems, s t rongly a l te r ing the ir s t ruc ture andfunct ioning, and would pr event the in t roduct ion of dam-

aging fishing techn iques like b ottom trawling in sensitivedeep-sea en vironm ents. However , th is gener a l measur ea lone needs to be comple ted with a para l le l s i te -baseda pproa c h to e nsu r ing a de qua te p ro te c tion o f t he mor ebiologically valuable deep-sea Mediterranean habitats.Indeed, some of the habitats listed above lie totally orpart ia l ly above the 1000 m isobath , as wi th Lopheliareefs in the Ionian Sea , some chemosynthe t ic commu-ni t ies , and submarine canyons and seamounts . Besides,even in tho se hab itats fully covered by the 1 00 0 m fishingban, fishing is not the only possible threat to be avoided

or alleviated: pollution, seafloor d rill ing, etc. would alsomer i t spec ific a t tent ion in a ny conserva t ion schem e.


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For these reasons, the se t t ing up of a representa t ivenetwork of deep-sea protec ted areas, endowed with ast r ic t management of major anthropic impacts , shouldbe a second key e lement of a regional pol icy for theconservation of deep-sea biodiversity, in full agreementwith decisions adopted at the CBD COP-7. Implementa-t ion of th is m easure would cer ta in ly benefi t from a wideconsensus among stakeholders , inc luding a l l potent ia lsec tors wi th an influence in the Medi te rran ean sea .

Submar i ne canyons

As descr ibed ear l ie r in th is report , submarine canyonsare geologica l s t ruc tures key to b io logica l and ecologi-ca l processes in the ent i re Medi te rr anean b asin . Indeed ,canyons are c ruc ia l in channel l ing energy and mat te rfrom coasta l a reas to the deep-sea , and by changingthe vorticity of currents creating local upwellings thatare crucial to the life-cycle biology of certain species,inc luding pe lagic f ish and marine mammals. Besides,important b iocoenoses such as those l inked to cold-wa-ter cor a ls a re assoc ia ted with the ir f lanks.

Canyons are also significant for Mediterranean fisheries,being tightly linked to the life cycle of aristeid shrimps,na tura l rep rod uct ive re fuges for overexploi ted dem ersa lspec ies, and impo rtant spawning grou nds for anch ovy.

Due to the three-dimen sional imp ortance o f canyons, a f-fecting both benthic and pelagic biodiversity, protectionshould be afforded at least to the entire canyon system,i .e . the sea f loor and the en t ire water colum n assoc ia tedwith it.

Scientific li terature shows that canyons are relevant toMedi te rr anean biodiversi ty and bio logica l pr ocesses a l la rou nd the r egion, thou gh they are esp ec ia lly impor tantin the NW Mediterranean (Catalonia, Gulf of Lions andLigurian coast ) , as wel l as in cer ta in p ar ts of the EasternBasin (i .e. those associated with the Nile fan, in the Le-vantine basin). A complete and fully representative net-work of deep-sea protec ted areas in the Region shouldconta in protec ted canyons systems from a t least thesetwo areas.

Col d seeps (chemosyntheti c communi ti es)

Deep-sea cold seeps a re o f maximu m eco logica l and bi-odiversi ty impor tance in the Med i te rr anean since , in theabsence o f deep-sea hydrother mal vents , cold seeps a rethe only fully chemosynthetic ecosystems in the basin.

Candida te s i tes for pro tec tion inc lude those cold seepswhere l ive chemosynthe t ic communit ies have beenidentified to d ate: the Olymp ic field ( South of Crete) , the

Anaximander mounta ins (South of Turkey) and a l im-ited ar ea o ff Egypt an d Gaza.

Munida rugosa.

Pr ince Alber t de Monaco . Camp. scient . Crustacs podopht. pl. VII.

J. Het del.Col l . Oceanograp h ic Museum, Monac o .


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It is l ikely that further research will demonstrate theexistence of more l ive chemosynthe t ic communit ies ino the r a re a s ha rb ou r ing mud vo lc a noe s a nd c o ld se e ps .Accordingly , the ne twork of deep-sea protec ted areascould , on a precaut ionary basis , a lso inc lude some ofthe a reas where cold seeps have been de tec ted , and thepresence of chemosynthe t ic communit ies is presumed.

Cold water coral reefs

Cold water cora ls reefs or mounds are of h igh b iodi-versity value in the Mediterranean. Only few relictualcolonies of the main cold water reef-bui lder Lopheliapertusa remain in the Medi te rranean, where i t appearstha t curren t environm enta l condi t ions a r e consider ablybelow the opt imum for th is spec ies. Madrepora ocu-lata i s another important reef-bui ld ing spec ies in the

Medi te rranean.Cold water reefs or mounds are b iodiversi ty hotspots ,s ince the assoc ia ted three-dimensional s t ruc ture pro-vides ecologica l n iches to Medi te rranean deep-seaspec ies such as the Medi te rranean orange roughy ( Ho-plostethus mediterraneus) a nd o the r s .

Obvious can dida te s i tes for pro tec tion inc lude the on lykn own live Lopheliamo unds in the Me d it e r ra ne a n thesi te found 20-25 miles offshore Santa Maria d i Leuca(I ta ly) , where th is b iocoenosis has been found a t ade p th ra nge o f 425 -1110 m a nd a fe w sc a tt e re d a re a sin the Albor an Sea, the Gulf of Lions and the Catalan Sea( a ssoc ia t ed to c a nyons) w he re the spe c ie s ha s be e n c on -f i rmed to occur . Other a reas of important Madreporaoculata presence could a lso be inc luded. Increasedpro spect ion will prob ably lead to the d iscovery of mor elive Lopheliaco lonies in the Medi te rranean .

Seamounts

Seamounts a re par t icular marine geomorphologica lst ruc tures tha t a re considered of grea t b iodiversi ty im-por tance worldwide . In a reas of the Ind ian and Pacificoceans, particularly, the discovery of significant bio-ma sse s o f c omm e rc ia l fi sh r e sou rc e s oc c u r r ing a roundthe slopes of seamounts has g iven way in recent yearsto the development of new deep-sea f isher ies . Thesehave systematically resulted in a strong decline of fishbiomass after only a few years of exploitation, due tothe very high vulnerability that the related deep-sea fishcom mu nit ies face to comm erc ia l exploita tion .

Although the biodiversity of Mediterranean seamountshas se ldom been explored, the f i rs t benthos samples

recovered from the top of the Era tosthenes Seamount ,in the Eastern Mediterranean, revealed a relatively rich

and diverse fauna tha t inc luded the fi rs t occurr ences o ftwo sclerac tinian spec ies in the Levant Sea, bo th of themconst i tu t ing the deepest records in the whole Medi te r-ranean. This and other sca t te red evidence suggest tha tMedi te rranean seamounts a re not an except ion in re la -tion to its biodiversity importance.

Even if a general l imitation on deep-sea fisheries asproposed ear l ie r could enta i l the par t ia l protec t ion ofsome Me d it e r ra ne a n se a moun t s , in m os t c a se s the sum -mi t a nd upp e r s lope s w ou ld re m a in unp ro te c t ed fa c e dwith potentially harmful fishing techniques such as bot-tom t rawling. Consequent ly , a s i te -based approach forthe protec t ion of Medi te rranean seamounts appears tobe necessar y. In th is sense , a Medite rranea n rep resenta-t ive ne twork o f deep-sea p rotec ted areas sh ould inc ludethe best known Medi te rranean seamounts , tha t i s , Era-

tosthenes, as wel l as , on a preca ut ionary basis , those ofpresumed biodiversi ty importance most threa tened bythe po tent ia l developm ent of an thropic ac t ivi ties ( nota-bly deep-sea f isher ies) .

Bri ne pools (deep hypersal i ne habitats)

Deep hypersa l ine s t ruc tures known as br ine pools a redeep-sea habi ta ts of h igh b iodiversi ty importance , par-t icular ly to extremophi l ic bac ter ia and metazoan meio-faunal assemb lages.

Reported si tes in the Medi te rranean are rest r ic ted to

the Eastern Basin, at beds below 3000-m. All i l lustrateddeep h yper sa l ine ano xic basins shou ld be inc luded in aMedi te rranean representa t ive ne twork of deep-sea pro-tec ted areas, to be preserved from potent ia l anthropicimpacts , such as seaf loor dr i l ling or waste d ispo sa l .


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Impl ementati on of a Medi terr anean network

of deep-sea protected areas

Differ ent legal po ssibilities exist for the es tablishm ent o fdeep-sea pr otec ted areas in the Medi te rranean , rangingfrom nat ional ( inc luding EU) legisla t ion , to in te rna t ion-

a l t rea t ies wi th com petence on the Medi te rr anean HighSeas, either dealing with integral conservation aspects

such as the Barce lona Convent ion or re la t ing to apart icular sec tor suc h as GFCM on fisher ies.

Given th is com plex pic ture , dur ing the d iscussion he ldat the CIESM thematic round table on the protection ofthe Medi te rranean deep-sea in June 2004, a need wasclearly identified by those experts present. A coordinat-ing p la t form should be c rea ted ga thering together a l lre levant t rea t ies with m andates for the pr otec t ion of the

Medi te rr anean and the m anagem ent of human ac t ivi tiesin th is sea , to m ove toward s a harm onized appro ach forthe establ ishment of a representa t ive ne twork of deep-sea pro tec ted area s in the Medi te rranean Sea .

This said, and given the usual slow pace of institutionalprocesses, the pr inc ip le out l ined above should not pre-vent se lec ted Medi te rranean deep-sea habi ta ts , such asthose p ropose d in the se c tions a bove ( se e ma p be low) ,a l ready be ing crea ted under the most appropria te lega lframework, to secure immedia te protec t ion . In th issense, i t is worth referring to the Ligurian Sea CetaceanSanctuary , c rea ted in 19 99 b y Fran ce , I ta ly and Monacoon the Medi te rranean High Seas, tha t was then desig-nated as one of the first Specially Protected Areas ofMedi te rranean Importance (SPAMI) under the Barce-lona Convention Protocol relative to Specially ProtectedArea s and Biological Divers ity in the Mediter ran ean .

Fig.9.Presen t ly known d is t r ibu t ion o f deep-sea un ique b iocenoses in the Medi ter ranean an d ad jacen t Atlan t ic waters .Cred i t : Hermes ( Hotspo t Ecosystem Research on the Mar g ins o f Europe an Seas) , VI FP Europ ean Comm ission Pro jec t ;a n d An Interacti ve Global Map of Sea Floor Topography Based on Satell i te Altimetry & Ship Depth Soundi ngs.Meghan Miller, Walter H.F. Smith, John Kuhn, & David T. Sandwell. NOAA Laboratory for Satellite Altimetry.http://ibis.grdl.noaa.gov. Modified.See colour plate, p. 57.


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Box 10. Community initiatives for the protection of deep sea biodiversityin Atlantic waters

Recent initiatives undertaken at European level haveser iously addressed the pr otec t ion of fragi le dee p-sea

habitats from trawling in the NE Atlantic. In March200 4, the European Coun ci l agreed to g ive perm anentpro tec tion to Scot lands un ique co ld-water cora l reefs ,the Darwin mounds, by banning deep-water bot tomtrawling in the a rea .

Only d iscovered in 1998, the Darwin Mounds (seebelow) are a unique col lec t ion of cold-water cora lm o u n d s ( Lopheli a pertusa) a t a de p th o f 1000 m,about 185km northwest of Scot land. They are madeup o f hundre d s o f c o ra l r e e fs up to 5m h igh a nd 100m

wide covering an area of approximate ly 100 sq km.The reefs support a wide diversity of marine life, suchas sponges, s ta rf ish , sea urchins, c rabs and deep-seaf ish inc luding the b lue l ing , round-nosed grenadiera nd o ra nge roughy.

Earl ie r , in February 2004 , the Euro pean Comm issiontabled a proposa l to ban the use of bot tom-trawled

fishing gear a round the Azores, Madeira and the Ca-nar y Islands (see m ap be low) . The dec lared a im is toe l iminate the r isk o f the last ing or i r repar able dam agetha t such gear can cause to h ighly sensi t ive d eep-waterhabitats found in these areas. A restrictive access re-gime has prevented until now the activity of deep-seatrawling in these a reas. The cont inenta l she lf a ro undthe i sl a nds c onc e rne d by the p r opose d me a su re s i svery nar ro w or virtually no n-existent. Severa l habitatsare to be found a t the bot tom of these deep waters .These inc lude deep-water cor a l aggregat ions, ther mal

vents and carbonate mounds, which g ive she l te r andfood to a highly diversified fauna and flora. Scientif-ic evidence , inc luding repo rts f rom the In terna t ionalCouncil for the Exploration of the Sea (ICES), showstha t habi ta ts such as those found around the is landsconcer ned by the pr opo sa l a re in need of spec ia l pro -tection, especially against the physical damage causedby bot tom trawls and similar fish ing gear .


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THE M EDITERRANEANDEEP - SEA ECOSYSTEMS.

ABELL, P., F. J. VALLADARESan d A. CASTELLN, 19 88 . Ana lysis ofthe s t ructure of decap od crus t acean as sem blages off theCatalan coast (North-West Mediterranean) . Mar. Biol., 98:3 9 - 4 9 .

ABELL, P. an d J. E. CARTES, 1992 . Populat ion char acter is t ics ofthe deep - sea lobs ter s Polycheles typhlopsan d Stereomas-ti s sculpta ( Decapoda, Polychel idae) in the Medi ter r ane-

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ABELL, P., J. M. ARCOSand L. GILDESOLA, 200 3. Geographicalpat terns o f seabi rd a t t endance to a r esearc h t r awler a longthe Iber i an Medi t er r anean coas t . Sci. Mar., 6 7 ( s u p p l. 2 ) :6 9 - 7 5 .

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The Mediterranean Deep-sea Ecosystems