Mediterranean Sea

Spatio-temporal distribution of soft-bottom epibenthic fauna on the Cilician shelf (Turkey), Mediterranean Sea Erhan Mutlu1 & Mehmet Betil Ergev2 1. Institute of Marine Sciences and Technology, Dokuz Eylul University, Inciralti, Izmir, Turkey; [email protected] 2. Derinsu Underwater Engineering & Consulting Company, Nilgun Sk. 5/1, Kavaklıdere, 06680 Ankara, Turkey Received 14-IX-2007. Corrected 16-V-2008. Accepted 18-VIII-2008. Abstract: Spatio-temporal distribution of epifauna collected with a sledge was studied on the Cilician shelf of the Mediterranean Sea. There were two different communities: the shallow community was restricted to water at 5 and 10 m deep with sandy bottom inhabited abundantly by Conomurex persicus, Arnoglossus laterna and Murex trunculus. Conomurex persicus, an introduced tropical species predominated the shallow zone and distinguished it from the deep zone. The deep community (25-150 m) lacked shallow water species and was dominated by Arnoglossus laterna, Goneplax rhomboides and Parapenaeus longirostris. Seasonality was not a major factor in the epibenthic community structure of the entire shelf, but it is in the shallow waters. Bottom depth was main factor for structuring the community on the shelf. Sediment size and organic content is also a controlling factor for the distribution of the epibenthic fauna. Rev. Biol. Trop. 56 (4): 1919-1946. Epub 2008 December 12. Key words: Epifauna, distribution, Cilician shelf, Eastern Mediterranean Sea. Mediterranean marine communities have a The diversity in the studied assemblage of greater diversity of small, short-lived individu- the Eastern Mediterranean was relatively poor als when compared to the Atlantic. Benthic spe- when compared with those from the Western cies richness in the Mediterranean is estimated sites (Cardel et al. 1999, Sarda et al. 1999, as approximately 7 250 with approximately 6 Gusso et al. 2001). According to the estima- 000 animals (Fredj et al. 1992). Recent number tions of Koukouras et al. (2001) updated out of species of some zoobenthic groups in the of a total of about 6 000 benthic invertebrate whole Mediterranean Sea was as follows: 1 species in the Mediterranean, about 67% (4 000 Polychaeta species, 2 000 Mollusca, 154 030) are found in the western Mediterranean, Echinodermata, 1 935 Arthropoda (Amphipoda 38% (2 262) in the Adriatic Sea, 35% (2 119) in 451, Decapoda 340, Isopoda 165, Anisopoda the Central Mediterranean, 44% (2 637) in the 43, Cumacea 91 and miscellaneous 845 spe- Aegean, and 28% (1 658) in the Levantine Sea. cies), 33 Sipuncula, 500 Bryozoa and 622 This trend in number of species demonstrates Porifera (UNEP/MAP 2004). Until December a west-east zoogeocline: a large number of 2005, alien species in the Mediterranean was geographic, climatic and trophic variables are estimated to be 745 species (Zenetos et al. highly correlated with this pattern which has 2005). Species richness in the Mediterranean been found to be similar for many taxonomic has been changing with the increasing number groups. Most benthic studies in the eastern of introduced lessepsian species (Bakir .et al Mediterranean Sea have been conducted in the 2006, Ozcan .et al 2006, Yokes et al. 2007, Aegean Sea end (Bellan-Santini 1985, Farina et Galil 2005, Yokes and Galil 2006, Horton et al. al. 1997a, Tselepides et al. 2000, Smith et al. 2004, Galil 2004, Cinar and Altug 2007). 2000, Kallianiotis et al. 2000). Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 56 (4): 1919-1946, December 2008 1919 To date, there are a few studies on the recently occurred in Argolikos Bay and Crete, epibenthic community from the Turkish coast of Greece, Zenetos et al. 2002) and examines the Mediterranean Sea, and no seasonal studies spatio-temporal distribution of the community on spatio-temporal distribution on epifauna. It in the investigated area, with regard to environ- is necessary to conduct such a study because it mental characteristics. is not possible to use estimates from other areas because the number of species varies among MATERIALS AND METHODS locations around the Eastern Mediterranean Sea. Ergen and Cinar (1997) reported 129 The study was conducted on a section Polychaeta (Annelida) species from Antalya of Levantine (Mediterranean Sea) continental Bay. Kocatas et al. (2004) recorded 81 crusta- shelf off Erdemli, Mersin Bay, Turkey (Fig. cean species as a Cystoseria facies (1 Cumacea, 1A). The Lamas River and a few brooks are 2 Tanaidacea, 23 Isopoda, 36 Amphipoda and the major source of terrestrial freshwater and 19 Decapoda) from the Turkish Aegean coasts organic input. Depth contours generally paral- whereas Kirim et al. (2005) found 85 species as lel the coast. There are no seagrass bed com- Padina facies and Ates et al. (2005) recorded a munities in the study area and only shallow total of 40 decapod species. rocky sites like the two harbors are covered Epifaunal studies by means of continu- by epilithic algae (Fig. 1B). Most dominant ously dredging could change ecological char- species of the shallow waters is Conomurex acterization of the community. This may be the persicus which inhabited on the sandy bottom case for the macrobenthic community inhab- with depth of generally 1 m to 10 m, extending iting the shallow sandy bottoms of the area down to 20 m (Mutlu and Ergev 2006). considered in this study. Frequent small-scale disturbances, such as dredging operations, may Benthic samples collection: Samples of thus be masked by large-scale environmental soft bottom epifauna were collected using the perturbations, such as storms, and prevailing epibenthic sledge of Hessler and Sanders (60 x hydrodynamic processes may be among the 15 cm mouth opening, 0.5 x 0.5 cm mesh size: key factors determining the extent to which Holme and McIntyre, 1971) deployed by R/V an area will be resilient to fishing disturbance Erdemli of Institute of Marine Sciences-Middle (Morello et al. 2006). The community structure East Technical University (IMS-METU) in the the continuously fished area was dominated study area (Fig. 1A). Sledges lasted about 15 by small, opportunistic, short-lived species min at 2 knots. Geographical coordinates were while the community structure of the recently fixed from GPS to estimate distance trawled on non-fished area was dominated by more fragile the bottom. and lon-living sessile organisms in dredged Each sample was washed in a sieve (0.5 and non-dredged fishing areas (Eleftheriou and mm square mesh). On board, samples with Robertson 1992, Simboura et al. 1998, Smith et total number of individuals higher than about al. 2000, Sarda et al. 2000, Gusso et al. 2001, 500 inds (i.e. a gastropod Conomurex per- Chicharo et al. 2002, Kamenos et al. 2003). sicus) were sub-sampled, with 3-5 jars each State of the papers reviewed above shows containing 70-90 randomly taken specimens that the Cilician shelf particularly large area preserved, and the rest of these samples were of Levantine Sea has not been considered only counted. with regard of the soft-bottom megafauna. Macrofaunal assemblages at the shallow The present study was the first seasonal mac- waters seem to be shaped by the sediment prop- robenthic epifaunal community study in the erties which are indeed more heterogeneous Mediterranean coast of Turkey, even in Turkish than those at the deeper areas (Karakassis and waters, particularly during post period of Eleftheriou 1997). Therefore, two sampling Conomurex persicus’ introduction (succession temporal frequencies were conducted with 1920 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 56 (4): 1919-1946, December 2008 43 Black Sea 42 A 41 40 Turkey 39 38 Study area 37 36 Meditarranean Sea 35 26 28 30 32 34 36 38 40 42 36.58 B 1 m 2 m 36.575 5 m 36.57 10 m Sandy 36.565 Campus of Institute of Marine Sciences 36.56 15 m Harbor 36.555 Muddy 36.55 34.255 34.26 34.265 34.27 34.275 34.28 36.65 25 m 36.65 36.65 36.65 25 m F 50 m C D E 50 m 36.6 100 m 36.6 36.6 36.6 100 m 150 m 150 m 36.55 36.55 36.55 36.55 36.5 36.5 36.5 36.5 36.45 36.45 36.45 36.45 36.4 36.4 36.4 36.4 February 2000 May 2000 August 2000 November 2000 Fig. 1.A. The study area; (B.) monthly sampling line stations (+) at 5 and 10 m depth contours at the shallow waters between February 2000 and April 2002; and (C-F) seasonal sampling line stations of the deep waters in February (C), May (D), August (E) and November (F) during year 2000. respect to the zones: shallow water and deep was composed of pure sand sediment (>99%) water of the Cilician shelf. and physically disturbed by currents, waves, climate and anthropogenic riverine sources. 1. Sampling frequency at shallow waters: In the Mediterranean Sea, the zone has been Shallow water has been restricted to depth gra- classified as a part of “fine, well-sorted sand” dient up to 10 m. Bottom of the shallow zone (SFBC, Peres 1982a). Makra and Nicolaidou Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 56 (4): 1919-1946, December 2008 1921 (2000) found two communities of the infralit- Laboratorial works: Epifaunal species toral zone, that of Muddy Sand in Sheltered and any demersal fish caught in the dredge Areas (SVMC) and that of SFBC under dis- were identified; counted and weighed (however, turbance and/or eutrophication in the Eastern total wet weight of polychaetes was measured Mediterranean. The zone was temporally very for each sample because most of the specimens dynamic and well-diversified in epifaunal spe- were fragmented).

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