Accidental entanglement of Mediterranean monk seals

ENDANGERED SPECIES RESEARCHEndang Species Res

Vol. 5: 205–213, 2008doi: 10.3354/esr00092

Printed December 2008Published online July 16, 2008

INTRODUCTION

Accidental entanglement of marine mammals,turtles and sea birds in fishing gear remains a globalproblem of immense proportions, as thousands of ani-mals representing non-target species fall victim to driftnets and other types of fishing gear (Alverson et al.1994, Morizur et al. 1999, Murray 2004, Kiszka & Muir2007). Marine mammals, such as pinnipeds, may beparticularly susceptible to severe population depletion(Read et al. 2006) because of their innate biologicalcharacteristics, being slow growing, long-lived ani-mals, with low fecundity. Accidental entanglement has

been reported to affect non-targeted populations ofseals around the world (Baker et al. 1998, Hanni & Pyle2000, Page et al. 2004).

The 3 members of the genus Monachus are the onlyseals to exclusively inhabit tropical and low-latitudetemperate waters; areas that have traditionally beensubjected to the greatest pressure from humans. TheCaribbean monk seal M. tropicalis is the only pinnipedknown to have become extinct and the Hawaiian monkseal M. schauinslandi is considered critically endan-gered (IUCN 2006). Accidental entanglement isconsidered a serious threat to the survival of monkseals (Henderson 2001). Once abundant throughout

© Inter-Research 2008 · www.int-res.com*Email: [email protected]

Assessing accidental entanglement as a threat tothe Mediterranean monk seal Monachus monachus

Alexandros A. Karamanlidis1,*, Evgenia Androukaki1, Stella Adamantopoulou1,Archontia Chatzispyrou1, William M. Johnson2, Spyros Kotomatas1,Anastasios Papadopoulos3, Vangelis Paravas1, Giorgos Paximadis4,

Rosa Pires5, Eleni Tounta1, Panagiotis Dendrinos1

1MOm/Hellenic Society for the Study and Protection of the Monk Seal, 18 Solomou Street, Athens 10682, Greece2The Monachus Guardian, c/o M. Schnellmann, Wernerstraße 26, 3006 Bern, Switzerland

3Fisheries Research Institute, Nea Peramos, Kavala 64007, Greece4WWF Greece, 26 Filellinon Street, Athens 10558, Greece

5Parque Natural da Madeira, Caminho do Meio, Funchal 9064-512, Madeira, Portugal

ABSTRACT: The Mediterranean monk seal Monachus monachus is the most endangered seal in theworld with <600 ind. currently surviving. The species faces a number of threats to its survival: acci-dental entanglement has been identified as one of the most important amongst them. Here we madethe first attempt to systematically describe the nature of this threat and assess its impact on Mediter-ranean monk seal populations. We based our study on information from an extensive literaturereview, questionnaires carried out in various locations in Greece and necropsies performed in Greeceand in the Madeira Islands, Portugal. Our results indicate that accidental entanglement has been,and still is, a major threat to the species in its main distribution area in the northeastern Mediter-ranean, and that this threat may increase throughout the seal’s range. Accidental entanglementoccurs mainly with fishing nets, and affects mostly sub-adult seals. Short-term conservation actionsshould include the identification of critical pupping sites and their protection through the establish-ment and enforcement of protective measures. A long-term course of action will require detailedknowledge of the causes of accidental entanglement of Mediterranean monk seals in fishing gear.

KEY WORDS: Endangered species · Mediterranean monk seal · Accidental entanglement ·Conservation · Seal-fishery interactions · Greece · Madeira

Resale or republication not permitted without written consent of the publisher

OPENPEN ACCESSCCESS

Contribution to the Theme Section ‘Fisheries bycatch: problems and solutions’

Endang Species Res 5:205–213, 2008

the Black Sea and the Mediterranean, and the coastand islands off northwest Africa, the Mediterraneanmonk seal M. monachus has been negatively affectedby anthropogenic activities since antiquity (Johnson &Lavigne 1999a) and is currently also critically endan-gered (IUCN 2006). Severe declines in abundance,especially in the last century, have largely reduced it to3 isolated populations (Johnson et al. 2006): the largestpopulation — ca. 250 to 350 ind. — survives in thenortheastern Mediterranean, mainly at remote loca-tions in the Ionian and Aegean Seas and the CilicianBasin (Güçlüsoy et al. 2004, Gucu et al. 2004, MOm2007a). Approximately 100 to 150 ind., which comprisethe single largest colony of the species, survive at CapBlanc at the Western Sahara (González et al. 2002),and 30 to 35 ind. survive in the Madeira Islands (Pireset al. 2008) (Fig. 1a).

Since the initiation of efforts to protect the Mediter-ranean monk seal, a number of threats have beenlinked to the species’ decline (Israëls 1992, Johnson& Lavigne 1998, Johnson et al. 2006). The most im-portant include deliberate killing due to competitionwith fisheries; human disturbance, e.g. habitat de-struction and fragmentation; and accidental entangle-ment and drowning in fishing gear.

Despite the early recognition of the negative impactof accidental entanglement to the Mediterraneanmonk seal, there has been no systematic attempt to un-derstand the causes, describe the nature and estimatethe impact of this threat to the status of the species. Inthis study, we describe the nature of accidental entan-glement and assess it as a threat to Mediterraneanmonk seal populations, discussing possible solutions tomitigate its future impact on the species.

MATERIALS AND METHODS

We based our study on data from 3 different sources:(1) a literature review, (2) data on Mediterranean monkseal bycatch collected through questionnaires carriedout in Greece and (3) data from necropsies collected dur-ing the monitoring of Mediterranean monk seal popula-tions in Greece and the Madeira Islands, Portugal.

Literature review. We carried out an extensive liter-ature review in search of information describing thenature of accidental entanglement of Mediterraneanmonk seals in fishing gear and the extent of this inter-action throughout the species’ range. We restricted oursearch to information from the 18th century to the1990s (first-hand field data from long-term monitoringprojects became available in the 1990s) that was foundin published and unpublished accounts included in theAnnotated Bibliography on Mediterranean monk seals(Karamanlidis & Johnson 2002).

Questionnaires on bycatch. In Greece, the Mediter-ranean monk seal is still widely distributed (Adaman-topoulou et al. 1999). Due to the extent of the species’range within the country (i.e. >15 000 km of coastlineand 3000 islands), the inaccessibility of its habitat andthe resulting difficulties in surveying such a large area,we carried out questionnaires among professional fish-ers, whom we considered to be the group most likely toprovide information on accidental entanglement ofMediterranean monk seals in fishing gear. The ques-tionnaires collected information on (1) number, loca-tion, stage of development (as defined by Samaranch &González 2000) and status (i.e. live or dead) of sealscaught in fishing gear; and (2) types of fishing gear thatthe seals were caught in.

Based on information on the diving behaviour ofMonachus monachus in the northeastern Mediter-ranean (Kiraç et al. 2002, Dendrinos et al. 2007) weconsidered 0 to 200 m as the depth range where themajority of seal–fishery interactions (and thus alsoentanglements) occur, and therefore carried out thequestionnaires only amongst coastal fishers — themain professional group operating at these depths.Questionnaires were carried out within 1 protectedand 2 unprotected areas in Greece: the main harbourof the island of Alonnisos in the National Marine Parkof Alonnisos, Northern Sporades (NMPANS) in thenorthwestern Aegean; the main harbour of the islandof Kalymnos; and several locations at the island of Za-kinthos. The NMPANS is the only protected area inGreece dedicated to the protection of the Mediter-ranean monk seal; the local seal population is consid-ered to be one of the most important in the easternMediterranean (Dendrinos et al. 1998). Protection isprovided through the strict protection of the species’main pupping sites and the enforcement of fishery reg-ulations. In the core zone of the NMPANS — which in-cludes the island of Piperi, where the main puppingsites are located, and an area of 3 nautical miles (nmiles) around it — all human activities, except scien-tific research and management of the island, arestrictly prohibited. In addition, throughout the rest ofthe park, medium-sized commercial fisheries (purseseine and trawler fishing) are not allowed to operatecloser than 1.5 n miles from the coasts of all islands.Kalymnos is an island of the Dodecanese, in thesoutheastern Aegean Sea (Fig. 1b) with one of thebiggest coastal fishing communities in Greece; Za-kinthos is located in the southern Ionian Sea (Fig. 1b).When selecting the unprotected study sites, we consid-ered one island in the Aegean and one in the IonianSea, both with a high number of monk seal sightingsand large coastal fishing fleets. Based on available in-formation (Adamantopoulou et al. 1999, DGMAF 2008)Kalymnos and Zakinthos fitted these considerations.

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Karamanlidis et al.: Accidental entanglement of Mediterranean monk seals

Necropsies. To monitor Mediterranean monk sealpopulations in Greece, MOm/The Hellenic Society forthe Study and Protection of the Monk seal, has beenoperating the National Rescue and Information Net-work (RINT) since 1991; RINT is alerted to the occur-rence of live and dead seal sightings from throughoutthe country (Adamantopoulou et al. 1999).

In the Madeira Islands the status of the Mediterraneanmonk seal has been monitored by the Parque Natural daMadeira Service (PNMS) since 1988 (Neves & Pires1999, Pires et al. 2008). The monk seals on these islandsare found mainly around the remote Desertas Islands(Fig. 1c), where they have been legally protected

through the establishment of the Desertas Islands NatureReserve (DINR) since 1990. The reserve boundary is de-fined by the 100 m isobath. The entire northern half ofthe park has partial reserve status, where the deploy-ment of fishing nets is prohibited. The southern half in-cludes the most important pupping sites for the speciesin the area (Karamanlidis et al. 2004), and has strictreserve status, where human activity — except tradi-tional tuna fishing — is prohibited.

Depending on the state of decomposition, necropsieswere performed on seals found dead in both Greeceand Madeira, with all necessary samples being col-lected for the diagnosis of the cause of death. The

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Fig. 1. Monachus monachus. (a) Distribution of theMediterranean monk seal. (b) and (c) Greece andMadeira Islands, respectively, indicating locationsmentioned in text. NMPANS: National Marine Park

Alonnisos, Northern Sporades


necropsies were performed by trained staff accordingto specific necropsy protocols for pinnipeds (Winchell1990) that have been adapted to the Mediterraneanmonk seal. Stages of development were determinedaccording to Samaranch & González (2000) and causesof death were assigned to the following categories• Non-human induced death (NHID): no evidence of hu-

man involvement in the death of the animal (e.g. dis-ease, drowning of pups due to bad weather conditions)

• Deliberate killing (DK): unequivocal evidence thatthe death was the result of deliberate human action(e.g. trauma from gunshot, harpoon or dynamite)

• Accidental death (AD): unequivocal evidence thatthe death was caused by non-deliberate humanaction (e.g. entanglement in fishing gear)

• Unknown cause of death (U): all cases where thecause of death could not be determined.Based on criteria identified by Kuiken et al. (1994)

we considered a seal to be accidentally entangled, ifthe following evidence was found:

(1) The animal was found entangled in nets and/ornet ropes

(2) Traumatic lesions were found that are specific forcapture in fishing gear, such as multiple, evenlyspaced, parallel wounds on the skin

(3) Evidence was found that is consistent with deathfrom immersion, such as fine persistent froth in the tra-chea and bronchi or bullae in the lung parenchyma

(4) Evidence of recent feeding, such as remains ofpartly digested or undigested prey, was found in thestomach.

RESULTS

Literature review

Mortality of Mediterranean monk seals from acci-dental entanglement in various types of fishing gearhas been reported from most parts of the species’ pre-vious range. Monk seals have been accidentallyensnared on baited hooks in the Danube Delta(Schnapp et al. 1962), in tuna nets in France in the1930s to 1940s (Cheylan 1974), in trammel gill nets inthe Bay of Tunis (Ben Othman et al. 1971) and inunspecified nets on the coast of Spanish Sahara (nowWestern Sahara) in 1913 (Boettger 1951). In theBalearic Islands, it was reported that entanglement,mostly in tuna nets, accounted for 9 deaths and wassecond only to shooting as a source of human-inducedmortality (Sergeant et al. 1978). In Algeria andMorocco, where 8 and 27 drownings were recorded,respectively, accidental entanglement was a majorsource of mortality up to the beginning of the 1990s(Anonymous 1990, Boutiba 1996).

Within the species’ current distribution range, acci-dental entanglement has also been reported as a causeof mortality. Research conducted with the use of ques-tionnaires in the Ionian islands of Greece in the early1990s indicated that accidental entanglement ac-counted for 23% of the 34 deaths recorded in the area(Panou et al. 1993). Similarly, research along the south-ern Aegean and western Mediterranean coasts ofTurkey in the mid 1970s indicated that entanglementcould almost rival shooting as a cause of mortality(Berkes et al. 1979); out of 7 known seal deaths, 3 couldbe attributed to drowning by entanglement. Prior tothe establishment of the DINR, the extensive use of gillnets and the frequent drowning of monk seals in aban-doned ‘ghost’ nets constituted a threat to the survivalof the small surviving monk seal colony at the DesertasIslands of Madeira (Anselin & van der Elst 1988, Neves1998). In contrast, the monk seal colony at Cap Blancappears to have been largely shielded from the effectsof accidental entanglement up until 1987, because ofwarfare and political instability that limited fishing inthe region.

Of the different types of fishing gear in which Medi-terranean monk seals are reported to have beenensnared (i.e. baited hooks and long-lines, tuna nets,gill nets), they appear to be most vulnerable to entan-glement in static gear and discarded nets in coastalareas (Harwood 1987, Panou et al. 1987, Israëls 1992).There is no evidence to suggest that in the past anyage or sex category was particularly vulnerable(Anonymous 1990).

Questionnaires

At the main harbour of the island of Alonnisos in theAegean Sea, 25 questionnaires were completed (cover-ing approximately 30% of the total population of fish-ers). All fishers interviewed worked mainly within theboundaries of the NMPANS. From the 21 responses re-garding accidental entanglement, only one reported tohave caught a sub-adult monk seal in a long-line thatsubsequently managed to free itself (Table 1). Fortyquestionnaires were completed at the main harbour ofthe island of Kalymnos (covering ca. 30% of the totalpopulation of fishers). All but one of the fishers inter-viewed was based at Kalymnos, although their fishingoperations extended throughout the central and south-eastern Aegean. Of the 40 responses regarding acci-dental entanglement, 4 reported to have capturedmonk seals (a total of 5 seals: 4 sub-adults, 1 adult).Four of these monk seals were found drowned in staticgear (i.e. gill nets), while 1 juvenile caught in a long-line managed to free itself (Table 1). At the island ofZakinthos 20 questionnaires were completed (covering

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approximately 35% of the total population of fishers).All fishers interviewed worked mainly around theisland of Zakinthos, but 4 also extended their fishingoperations to Cephalonia in the north and the westerncoasts of the Peloponnese in the east. Five fishersreported having caught a total of 7 seals in their gillnets. All of these were sub-adults and only 2 werealive and subsequently freed (Table 1).

Necropsies

From 1991 to 2007, 200 dead monk seals were re-ported to the RINT in Greece; in 96 cases full necropsieswere carried out. In 104 cases nonecropsy was carried out, either be-cause the recovered carcass was alreadytoo decomposed or because MOm wasinformed too late and the carcass had al-ready been disposed of. Accidental en-tanglement in fishing gear was deter-mined as the cause of death in 7 femalesubadult Mediterranean monk seals,found in Zakinthos (n = 2), Naxos,Samos, Evoia (n = 2) and Lavrio. It wasthe second most frequently recordedhuman-related cause of mortality andthe 4th overall (NHID, DK and AD ac-counted for 40, 16, and 8% of all cases,respectively; the cause of death couldnot be determined in 36% of the cases)(Table 2). Entanglement appeared to af-fect mainly sub-adult individuals(46%). In contrast, the most frequentlyrecorded mortality cause in adults wasdeliberate killing (50%) and NHID inpups (93%). No death through acciden-tal entanglement was recorded withinthe NMPANS.

In the Madeira Islands (1989 to2007), PNMS recorded 7 dead monkseals (5 pups, 2 sub-adults) and 1 sub-adult hooded seal Cystophora cristata.One monk seal pup and the sub-adulthooded seal died of NHID, while therest died of unknown causes. No caseof accidental entanglement was re-corded.

DISCUSSION

Effective protection and manage-ment of endangered species requiresthe detailed understanding of the

causes, nature and magnitude of the mortality factorsthat affect it. In the case of the critically endangeredMediterranean monk seal, the species’ low populationnumbers, its retiring nature and the inaccessibility ofits habitat have hampered scientific research thatcould provide insights into such issues (Güçlüsoy et al.2002). In addition, research related to mortality causesfaces inherent difficulties, such as bias in data collec-tion and statistical errors in data analysis, and is there-fore capable of delivering only an approximation of thetrue nature of the phenomenon. Considering these dif-ficulties, we believe that the numbers of seals caughtaccidentally in fishing gear recorded during our studyrepresent a minimum of animals actually caught.

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Number of Type of Location Seal development Sealseals caught fishing gear stage status

1 Long-line NMPANS Sub-adult Alive1 Gill net Rhodes Sub-adult Dead1 Gill net Karpathos Sub-adult Dead1 Gill net n.a. Adult Dead1 Gill net n.a. Sub-adult Dead1 Long-line Kos Sub-adult Alive1 Gill net Zakinthos Sub-adult Dead1 Gill net Cephalonia Sub-adult Alive1 Gill net n.a. Sub-adult Alive1 Gill net W Zakinthos Sub-adult Dead1 Gill net S Cephalonia Sub-adult Dead1 Gill net N Cephalonia Sub-adult Dead1 Gill net Zakinthos Sub-adult Dead

Table 1. Information from questionnaires on accidental ensnarement of Mediter-ranean monk seals in fishing gear. n.a.: information not available, NMPANS:

National Marine Park of Alonnisos, Northern Sporades

Year Deliberately Ensnarement Non-human- Unknownkilled induced death cause

1991 0 0 1 01992 0 0 2 01993 2 1 0 01994 1 0 5 01995 0 1 2 11996 1 0 3 21997 1 0 4 31998 1 0 1 11999 2 0 4 12000 1 1 3 42001 0 2 2 62002 1 0 2 22003 2 0 0 42004 1 0 3 42005 0 1 1 22006 2 0 2 32007 0 1 4 2Total 15 7 39 35

Table 2. Monachus monachus. Necropsies carried out in Greece (1991–2007)and causes of death determined. Ensnarement: accidental ensnarement in

fishing gear


Accidental entanglement has posed a threat to thespecies since antiquity (Johnson & Lavigne 1999a,Johnson 2004). Although it is impossible — due to theconstraints mentioned above — to accurately estimatethe impact of accidental entanglement on the status ofthe species, the results of our literature review indicatethat this mortality cause has probably played an impor-tant role in the extirpation of the species from severalareas of its previous distribution, and that in somecases accidental entanglement could have rivalleddeliberate killing as the most important human-relatedmortality cause. A similar picture arises from theanalysis of the data obtained from the questionnairesand the necropsies carried out in Greece, where acci-dental entanglement and subsequent drowning ofseals has been recorded in areas where there is noeffective protection of important pupping sites and nofishing regulations are in force. Despite the earlierbelief that no age class was particularly vulnerable tothis type of mortality (Anonymous 1990), the results ofthe research in Greece indicate that sub-adult monkseals may be especially prone to entanglement. Thisfact is corroborated by circumstantial evidence fromthe Aegean coast of Turkey, where accidental en-tanglement in fishing nets has been blamed for severalrecent deaths of pups and sub-adults (Veryeri et al.2001). We speculate that individuals of this age classmight be less cautious and less experienced thanadults when approaching nets. Considering the limitedamount of data collected to date, further monitoring isrequired in order to substantiate this hypothesis.

Regarding the type of fishing gear mostly affectingMediterranean monk seals in Greece, our evidencesuggests that static nets pose the highest threat, as allanimals reported as caught in long-lines subsequentlymanaged to free themselves. This finding is in accor-dance with findings in the past throughout the species’range (Harwood 1987, Panou et al. 1987, Israëls 1992).

Accidental entanglement is currently not a threat tothe Mediterranean monk seal in the Madeira Islands.This is due to the prohibition of the use of gill netsthroughout the entire Madeira Islands in combinationwith the strict protection and the fishing regulationsenforced around the main pupping sites of the speciesat the Desertas islands. The results of the presentstudy justify the decision of PNMS to provide incen-tives to local fishers to switch from using static fishingnets to using alternative forms of fishing, such aslong-lines (Pires & Neves 2001). Considering, how-ever, the fact that the species is showing encouragingsigns of recovery in its repopulation of the main islandof Madeira, and that interactions of Mediterraneanmonk seals with fisheries have increased (Pires et al.2008), accidental entanglements might occur in thenear future.

At Cap Blanc up to the 1990s accidental entangle-ment was considered not to pose a threat to the sur-vival of the species due to the political instability in theregion. With the resumption of both industrial and arti-sanal fishing in the area, however, (Zeeberg et al.2006), the risk of accidental entanglement has re-turned in force. Although no deaths have been directlylinked to fishery interactions, there is concern thatseals may fall victim to entanglement in the future(Anonymous 1990, González et al. 2002).

Considering the low population levels of Mediter-ranean monk seals, our study indicates that accidentalentanglement has represented and still does repre-sent a threat to the survival of the species in a largepart of its range in the northeastern Mediterranean.Furthermore, considering the fact that human pres-sure on coastal ecosystems in the Mediterraneanbasin in the near future will increase (Johnson & Lavi-gne 1999b) and that fishing pressures might, in turn,increase in response to regional demand, it is proba-ble that the threat of accidental entanglement on thesurvival of the species will also increase throughoutits range, unless appropriate conservation measuresare taken.

In addressing the problem of accidental entangle-ment, one needs to understand the reasons whyMediterranean monk seals raid fishing gear. In thisrespect, 2 separate assumptions have been advancedto explain the seals’ behaviour. The first relates to theinnate tendency of every species to conserve energyand seek food at the most convenient of places, whilethe second relates to the overfishing of coastal areaswithin the species’ distribution range (Johnson & Kara-manlidis 2000). There is insufficient evidence to sub-stantiate any of these theories; this shortcoming in theunderstanding of the causes of accidental entangle-ment is currently addressed by an EU-funded LIFEproject (MOm 2007b).

Regardless of the reasons that drive Mediterraneanmonk seals towards fishing nets, and considering theurgency for conservation measures that will effectivelyprotect the species, 2 protection measures are mostlikely to be considered in the near future: the use ofacoustic deterrents and the establishment and enforce-ment of fishing regulations.

Taking into account the mixed long-term resultsacoustic deterrents have had in driving seals awayfrom fishing nets, and their cost (Pemberton & Shaugh-nessy 1993, Yurk & Trites 2000, Fjälling et al. 2006), aswell as the large number of fishers and the large extentof the area in which such conservation actions wouldhave to take place, we do not believe that the use ofsuch devices represents a viable solution to the prob-lem of accidental entanglement of Mediterraneanmonk seals in fishing gear.

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In contrast, fishing regulations at and around criticalpupping sites, such as those currently in force at theNMPANS and DINR (i.e. no fishing allowed at a dis-tance of 3 n miles around the main pupping sites at theNMPANS, no fishing allowed around the main pup-ping sites within the area between the coast and the100 m isobath at the DINR), have managed to elimi-nate the threat of accidental entanglement to the monkseal populations in both areas.

CONCLUSIONS

Mediterranean monk seals are currently threatenedwith extinction. Amongst the array of threats that jeop-ardise their survival, accidental entanglement ranks asone of the most important. Conservation actions thataim to mitigate the effects of this threat should includethe identification of important pupping sites of the spe-cies and their effective protection through specifichuman activity and fishing regulations (i.e. creation ofmarine protected areas, MPAs). Such conservationactions would maximise the survival chances of sub-adult seals, while at the same time increasing fishstocks and providing fishing opportunities to localcommunities through spillover of exploitable fishesfrom the protected areas (McClanahan & Mangi 2000).Thus MPAs are the most realistic and viable short-termsolution to the problem of accidental entanglement ofMediterranean monk seals in fishing gear.

However, an effective and long-term solution to theproblem cannot be provided unless the causes of thisthreat are fully understood. Further research into thecauses of accidental entanglement of Mediterraneanmonk seals in fishing gear should be one of the out-standing research priorities in the near future.

Acknowledgements. RINT’s operation and necropsies inGreece have been carried out with the financial support of EUprojects Contract Nos. 4-3010(92)7829 and B4-3040/95/009/AO/D2, LIFE/Nature project LIFE96NAT/GR/ 3225, LIFE00NAT/GR/7248 and the MOFI LIFE project (LIFE05NAT/GR/000083). MOm expresses its gratitude towards all mem-bers of RINT and the volunteers that assisted in this work. Thequestionnaire part of the study in Greece was carried out aspart of the MOFI LIFE project (LIFE05NAT/GR/000083).MOm thanks the presidents of the fishing cooperativesof Kalimnos and Zakinthos, Mr. G. Katsotourchis and N.Paraschis, who assisted greatly in organising the question-naire study. We thank Andrew Cunningham and 3 anony-mous reviewers for their constructive comments in the prepa-ration of this document. Lastly, MOm thanks all fishers whoparticipated in the questionnaires, and the Hellenic Ministryof Rural Development and Food for its support and for provid-ing research permits. In the Madeira Islands, necropsies wereperformed with the invaluable assistance of the Seal Rehabil-itation and Research Centre, the Regional Secretary of Fish-eries, the City Council of Funchal and the Regional Veteri-nary Lab, as well as the Institute of Virology of the University

of Rotterdam in Holland. The Marine Mammal FisheriesNetwork (http://groups.yahoo.com/group/Marine_Mammal-Fisheries_Network) was instrumental in coordinating actionsin preparing this manuscript.

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Editorial responsibility: Andrew Cunningham,London, UK

Submitted: November 4, 2007; Accepted: March 17, 2008Proofs received from author(s): July 10, 2008

Documents

Accidental entanglement of Mediterranean monk seals