ICES Journal of Marine Science, 59: S192–S195. 2002doi:10.1006/jmsc.2002.1221, available online at http://www.idealibrary.com on

Short communication

Artificial reefs in Turkey

Altan Lok, Cengiz Metin, Ali Ulas,F. Ozan Duzbastılar, and Adnan Tokac

Lok, A., Metin, C., Ulas, A., Duzbastılar, F. O., and Tokac, A. 2002. Artificial reefsin Turkey. – ICES Journal of Marine Science, 59: S192–S195.

Artificial reef deployment in Turkish waters and results from monitoring studies aredescribed. The first known project with 10 old trolley-bus bodies was in 1989, andpresently there are six ongoing projects in which reinforced concrete modules of fivedifferent designs are being used. The main aims are: (1) to protect fish-spawning andnursery areas from illegal trawling; (2) to create new sites for recreational fishing anddiving; (3) to protect small-scale artisanal fisheries from damage caused by illegaltrawling; and (4) to conduct scientific experiments. Most projects are supported bylocal municipalities and fishery cooperations. Following a meeting of the experts andfoundations involved, a ‘‘Project Guide for Artificial Reef Applications’’ has beenproduced recently which formulates the requirements that must be met by all newartificial reef projects along Turkish coasts.

� 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd.All rights reserved.

Keywords: Aegean Sea, artificial reef, legal regulations, planning.

Accepted 11 December 2001.

A. Lok: Aegean University, Faculty of Fisheries, Urla-Iuskele, Iuzmir, Turkey; tel:+90 232752 11 62 (12); fax: +90 232 388 36 85; e-mail: lok@sufak.ege.edu.tr

Introduction

Previous studies conducted on pelagic (Kocatas et al.,1993) and demersal (Tokac et al., 1998; Metin et al.,2000) fish populations off Turkish coasts show thatcatches comprise mainly sub-adult fish. This sign ofoverfishing is particularly obvious in demersal fishstocks of the Aegean Sea. Illegal trawling, coastlinedevelopment, pollution, and damage to Posidoniaoceanica meadows are the main factors affecting marineecosystems along the Turkish Aegean coast.

Trawling is prohibited within 2.5 km from the coast inregions where depth increases sharply, and within 5 kmwhere the seabed slopes gently. Illegal trawling is afrequent occurrence, especially in the latter case. Arti-ficial reefs have been suggested as a solution to en-forcing the trawling ban. Small-scale artificial reefs weredeployed mainly along the Aegean Sea Coast of Turkey(Figure 1).

The metropolis municipality deployed 10 old trolley-bus bodies in Iuzmir Bay in 1989 to create the firstTurkish artificial reef project. The first scientific artificial

1054–3139/02/0S0192+04 $35.00/0 � 2002 International Council for the E

reef project, conducted by the Aegean UniversityFaculty of Fisheries, was started later in Hekim Island,Iuzmir Bay, in 1991. Thirty cubic concrete blocks wereassembled in six pyramids (four blocks forming thebase, with one on top). The perceived success of thisproject resulted in increased interest in reef technologyand new cooperative projects were started among localgovernments, fishery cooperations, and universities.Local governments provided financial support, universi-ties provided scientific and technical knowledge, andfishery cooperations provided practical informationon local conditions. So far, five artificial reef projectshave been completed. The structural and ecologicalfeatures of these and other experimental projects aresummarized in Table 1. Four new projects are in theplanning stage.

The main aims have been: (1) to protect fish-spawningand nursery areas (e.g. Posidonia meadows) from illegaltrawling; (2) to create new sites for recreational fishingand diving; (3) to protect small-scale artisanal fisheriesfrom damage caused by illegal trawling; and (4) toconduct scientific experiments.

xploration of the Sea. Published by Elsevier Science Ltd. All rights reserved.

S193Artificial reefs in Turkey

Construction materials and designs

In January 1999, the Turkish Ministry of Agricultureand Rural Affairs prohibited the use of waste materialsin artificial reef construction; only concrete, PVC, andsteel may be used currently. In all projects since 1989,reinforced concrete modules designed in accordancewith scientific rationales have been used. To date, therehave been five different modules (Figure 2), four ofwhich are multi-purpose and one is species-specific (foroctopus).

Deployment techniques vary. While octopus reef unitswere positioned one-by-one using a crane, modules in

the Hekim Island Project were deployed by craneaccompanied by divers. In other projects, modules weredeployed by free falling technique.

38°00'

0 15 30km

39°00'

38°30'

27°00'26°00'

Aegean SeaArtificial reef area

7

8

GümüldürÜrkmez

152

UriaDalyanköy

43

6 Foça

NTurkey

Izmir.

N

E

Figure 1. Artificial reef sites in Turkey: 1. U} zmir Inner Bay,2. Hekim Island, 3. Dalyankoy, 4. Gulbahce, 5. Urla, 6. Foca,7. U} rkmez, 8. Gumuldur.

Table 1. Structural and ecological features of artificial reef projects in Turkey.

Locality PurposeDepth

(m)Trophicstatus

Natural reeflocation

(km)

Agein

2001 Material Design

Totalvolume

(m3) Data

Iuzmir Inner AT1 20–40 E5 Unknown 12 Old Body 600 No dataBay LF2 trolleysHekim Ex3 9–18 E 0.5 9 RC7 Cubic 30 Species list of fish,Island algae and benthosDalyankoy MP4 20 O6 2 6 RC Cubic 100 Species list of fish

Plus shapeUrla Ex 6 E 0.01 4 RC Octopus 55 Under observation

reefU} rkmez MP 18–22 O 6 3 RC Pentagon 320 Species list of fish

domeGumuldur MP 16–22 O 5 3 RC Cubic 310 Under observationFoca MP 30 O 0.5 7 RC Plus shape 30 No dataIuzmir Bay AT 15–25 E 0.5 2 RC Multi Unknown No data

floor

1Anti-trawl; 2line fisheries; 3experimental; 4multi-purpose; 5eutropic; 6oligotrophic; 7reinforced concrete.

(a) (b) (c) (d) (e)

Figure 2. Designs of artificial reef units used in Turkey: A –hollow cube (1.2 m3); B – plus shape (1 m3); C – pentagon dome(base 0.8 m2, 1.5 m high); D – octopus (base 1 m2, 0.4 m high,hole diameter 0.018 m); and E – multi-holes (1.5�0.3�0.4 m).

Monitoring studies

The number of available monitoring studies is limited.While detailed observation studies were carried out inthe Hekim Island Project, only a fish species list wasobtained from the Dalyankoy and U} rkmez projects. Inall studies, fish abundance and the presence of macro-invertebrates were determined by SCUBA divers usingvisual census techniques.

In the Hekim Island Project, hollow 1 m3 concreteblocks were deployed at two different depths (15 at both9 m and 18 m depth). The blocks were arranged in apyramid (four at the base and one on top) by divers.Eight fish species identified before deployment had risento 16 after 1 year (Table 2). Differences between speciesnumber and number of individuals before and after reefdeployment were significant (t-test, p<0.05; Lok andTokac, 2000). During a recent study (in 2000), 8 yearsafter deployment, 22 species belonging to 13 families

S194 A. Lok et al.

were identified (Table 3), an increase of nearly 40%compared to the first study.

The number of species and individuals at the 9-m and18-m reef varied seasonally. Both increased during thesummer months and decreased in winter at 9-m depth,while the reverse trend was observed at 18-m depth. Forboth metrics, differences between the two reefs weresignificant (t-test, p<0.05). A similar seasonal fish mi-gration has been suggested in other studies (Bombaceet al., 1989; Bohnsack et al., 1991).

Fish species around the reef were evaluated in accord-ance with the classification of Bohnsack et al. (1991) asresident species (54–100%), visitor species (42–56%), ortransient species (0–42%). The results (Table 2) suggestthat depth is important in attracting visitor species, butnot in the case of resident species (Moffitt et al., 1989).

A total of 100 algal species have been recorded fromthe reef (35 Cyanophyceae, 35 Rhodophyceae, 18Phaeophyceae, and 12 Chlorophyceae; Dural et al.,1997) and 25 invertebrate species belonging to 7 phyla(Cnidaria, Annelida, Arthropoda, Mollusca, Bryozoa,Echinodermata, and Ascidiacea).

Fifty cubic and 50 ‘‘plus-shape’’ design (Figure 2) reefunits were used in the Dalyankoy Project in July 1995,each group consisting of 25 units deployed at 20 m atintervals of 100 m.

Only a fish species list has been obtained, and thisincluded 19 species belonging to seven families (Table 3).Thirteen species were classified as residents, five asvisitors and one as transient, and 58% of the species wereof economic value.

The U} rkmez Project was carried out in a coastal areawith Posidonia meadows extending to 18 m depth,beyond which a muddy seabed area starts. ‘‘Pentagon’’dome-shaped units (Figure 2) were deployed to protectthe meadows from illegal trawling. A total of 16 reefgroups, consisting of 20 units each at intervals of 100 m,were deployed parallel to the coast, protecting 2 km2.Fifteen species belonging to 11 families were identified(Table 3) during underwater observations in 2000.

Legal regulations

Until October 1999, there were no legal regulations inrelation to reef projects; it was sufficient merely toinform the Ministry of Agriculture and Rural Affairsabout planned projects. After arranging a meeting withreef stateholders in September 1999, a ‘‘Project Guidefor Artificial Reef Applications’’ was prepared andrecommendations were put forward to establish rules forthe planning and implementation of artificial reefprojects. The guidelines consist of six parts: (1) descrip-tion, (2) procedures, (3) objectives, (4) site selectioncriteria, (5) construction materials, and (6) design.Although still far from fully covering all biologicaland engineering aspects, the guidelines represent animportant starting point.

Table 2. List of fish and other mobile species observed (p/a: presence/absence) before (B) and after (A)reef deployment and frequency of occurrence (FoC in %) by depth (Cl: classification as resident – R,visitor – V, or transient – T), and information on species richness and total abundance (�s.d.).

Family Speciesp/a FoC

18 mB A 9 m Cl

Atherinidae Atherina boyeri — + 14 0 TCentracanthidae Spicara smaris + + 56 0 VGobiidae Gobius niger — + 0 28 TLabridae Coris julis + + 56 70 R

Symphodus ocellatus + + 14 28 TMullidae Mullus barbatus — + 0 14 TSerranidae Serranus scriba + + 84 100 RSparidae Diplodus annularis + + 70 70 R

Diplodus vulgaris + + 56 100 RBoops boops + + 42 0 VLithognathus mormyrus — + 14 0 TSparus aurata — + 14 0 TSarpa salpa — + 42 0 TSpondyliosoma cantharus — + 14 0 T

Pomacantridae Chromis chromis — + 56 28 VOctopodidae Octopus vulgaris + + 42 42 VMean no. species 4.6�0.6 7.3�0.6Mean no. individuals 134�25 259�56

Future developments

There is as yet no national or regional artificial reef

project in Turkey. Despite the absence of subsidies from

S195Artificial reefs in Turkey

the national government, some small-scale projects arebeing carried out locally. In particular, the number ofprojects aimed at protection is increasing. However,given the limited number of monitoring studies and alack of basic knowledge on for instance local cur-rent and wave conditions, it is not realistic to expectthorough evaluations of the effectiveness of artificialreefs until more extensive baseline data are collected.

Table 3. Fish species list from three reef sites sampled in 2000.

Family SpeciesHekimIsland Dalyankoy U} rkmez

Congridae Conger conger + +Carangidae Lichia amia + +Serranidae Serranus cabrilla + + +

Serranus hepatus + +Serranus scriba + +

Scianidae Sciaena umbra +Mullidae Mullus barbatus + +

Mullus surmuletus +Sparidae Sparus aurata + + +

Boops boops + + +Dentex dentex + +Diplodus annularis + + +Diplodus sargus +Diplodus vulgaris + + +Oblada melanura +Puntazzo puntazzo +Spondyliosoma cantharus +

Centracanthidae Spicara maena maena + +Spicara smaris + + +

Pomacentridae Chromis chromis + + +Labridae Labrus merula +

Coris julis + + +Symphodus tinca + +Thalossoma pavo +

Gobiidae Gobius niger + +Blennidae Parablennius rouxi +Tripterygiidae Tripterygion tripteronotus +Atherinidae Atherina boyeri +Scorpaenidae Scorpaena porcus + +Octopiidae Octopus vulgaris +

References

Bohnsack, J. A., Johnson, D. L., and Ambrose, R. F. 1991.Ecology of artificial reef habitats and fishes. In ArtificialHabitats for Marine and Freshwater Fisheries, pp. 61–107.Ed. by W. Seaman, and L. M. Sprague. Academic Press,London.

Bombace, G., Fabi, G., and Fiorentini, L. 1989. Preliminaryanalysis of catch data from artificial reefs in the centralAdriatic. FAO Fisheries Report, 428: 120–127.

Dural, B., Aysel, V., Lok, A., and Guner, H. 1997. Benthicalgal flora of the natural and artificial substrata of HekimIsland (Iuzmir, Turkey). Algological Studies, 85: 31–48.

Kocatas, A., Koray, T., Kaya, T., and Kara, O} . F. 1993.Review of the fishery resources and their environment in theSea of Marmara. GFCM. Studies and Reviews, 64(Part 3):87–143. Rome.

Lok, A., and Tokac, A. 2000. Turkey: A new region forartificial habitats. In Artificial Reefs in European Seas,pp. 21–30. Ed. by A. C. Jensen, K. J. Collins, and A. P. M.Lockwood. Kluwer Academic Publishers, Dordrecht.

Metin, C., Tosunoglu, Z., Tokac, A., Lok, A., Aydın, C., andKaykac, H. 2000. Seasonal variations of demersal fish com-position in Gulbahce Bay (Iuzmir Bay). Turkish Journal ofZoology, 24: 437–446.

Moffitt, R. B., Parrish, F. A., and Polovina, J. J. 1989.Community structure, biomass and productivity of deepwa-ter artificial reefs in Hawaii. Bulletin of Marine Science, 44:616–630.

Tokac, A., Lok, A., Tosunoglu, Z., Metin, C., and Ferro,R. S. T. 1998. Cod-end selectivities of a modified bottomtrawl for three fish species in the Aegean Sea. FisheriesResearch, 39: 17–31.