Scientia Marina, Vol 70, No 4 (2006)

Molluscan diversity along a Mediterranean soft bottom sublittoral ecotone

Panayota Koulouri
Hellenic Centre for Marine Research, Institute of Marine Biology and Genetics, Greece

Costas Dounas
Hellenic Centre for Marine Research, Institute of Marine Biology and Genetics, Greece

Christos Arvanitidis
Hellenic Centre for Marine Research, Institute of Marine Biology and Genetics, Greece

Drosos Koutsoubas
University of the Aegean, Department of Marine Science, Greece

Anastasios Eleftheriou
University of Crete, Department of Biology, Greece


Molluscan diversity associated with sublittoral soft-bottoms was studied in Heraklion Bay as part of a long-term multidisciplinary research programme in the coastal environment of northern Crete (eastern Mediterranean). Quantitative benthic samples were collected in a pilot survey from a grid of 28 stations, followed by a seasonal sampling carried out over a seven- station transect located from 10 to 40 m depth. Univariate and multivariate analyses indicated the presence of a clear zonation along the depth gradient for the molluscan fauna and three main associations were identified in bathymetric zones parallel to the coastline. The structure of the local molluscan communities revealed the existence of an extended transition zone (ecotone) between a shallow sandy association and a deeper muddy one and a functional pattern, based on the feeding guilds, was evident along the environmental gradient. Application of graphical techniques, by using molluscan taxocoenosis, indicated a rather naturally disturbed habitat. Beta-diversity measures indicated different seasonal community adaptations to the prevailing environmental conditions. Results derived from this study revealed that beta-diversity may be a good descriptor for the assessment of the strength and breadth of sublittoral transition zones along environmental gradients.


mollusc diversity; ecotone; sublittoral; soft bottom; beta-diversity; perturbation; environmental assessment; eastern Mediterranean

Full Text:



Attrill, M.J. and S.D. Rundle. – 2002. Ecotone or Ecocline: Ecological Boundaries in Estuaries. Estuar. Coast. Shelf Sci., 55: 929-936. doi:10.1006/ecss.2002.1036

Bellan-Santini, D. – 1985. The Mediterranean Benthos: Reflections and problems raised by a classification of the benthic assemblages. In: M. Moraitou-Apostolopoulou and V. Kiortsis (eds.), Mediterranean Marine Ecosystems, pp. 19-48. Plenum Press, New York.

Borja, A., J. Franco and V. Pérez. – 2000. A Marine Biotic Index to Establish the Ecological Quality of Soft-Bottom Benthos Within European Estuarine and Coastal Environments. Mar. Pollut. Bull., 40(12): 1100-1114. doi:10.1016/S0025-326X(00)00061-8

Bray, J.R. and J.T. Curtis. – 1957. An ordination of the upland forest communities of southern Wisconsin. Ecol. Monogr., 27: 325-349. doi:10.2307/1942268

Carey, J.M. and M.J. Keough. – 2002. Compositing and subsampling to reduce costs and improve power in benthic infaunal monitoring programs. Estuaries, 25(5): 1053-1061.

Clarke, K.R. and M. Ainsworth. – 1993. A method of linking multivariate community structure to environmental variables. Mar. Ecol. Prog. Ser., 92: 205-219. doi:10.3354/meps092205

Clarke, K.R. and R.M. Warwick. – 1994. Change in marine communities: an approach to statistical analysis and interpretation. Natural Environment Research Council, Plymouth Marine Laboratory.

Corbera, J. and M.J. Cardell. – 1995. Cumaceans as indicators of eutrophication on soft bottoms. Sci. Mar., 59(Suppl. 1): 63-69.

Costello, M.J., G. Pohle and A. Martin. – 2004. Evaluating biodiversity in marine environmental assessments. Research and Development Monograph Series 2001, Canadian Environmental Assessment Agency, Ottawa.

Delamotte, M. and E. Vardala-Theodorou. – 2001. Shells from the Greek Seas. The Goulandris Natural History Museum, Athens.

Dewarumez, J., D. Davoult and S. Frontier. 1992. – Is the “Muddy Heterogenous Sediment Assemblage” an ecotone between the pebbles community and the Abra alba community in the Southern Bight of the North Sea? Neth. J. Sea Res., 30: 229-238. doi:10.1016/0077-7579(92)90061-I

Dounas, C. and K. Papadopoulou. – 1993. Oceanographic and environmental study of Iraklion Bay. Tech. Rep., Institute of Marine Biology of Crete, Greece (in Greek).

Gómez-Gesteira, J.L. and J.C. Dauvin. – 2000. Amphipods are good bioindicators of the impact of oil spills on soft-bottom macrobenthic communities. Mar. Pollut. Bull., 40(11): 1017-1027. doi:10.1016/S0025-326X(00)00046-1

Graf, G. – 1992. Benthic-pelagic coupling: a benthic view. Oceanogr. Mar. Biol., 30: 149-190.

Gray, J.S. – 2000. The measurement of marine species diversity, with an application to the benthic fauna of the Norwegian continental shelf. J. Exp. Mar. Biol. Ecol., 250: 23-49. doi:10.1016/S0022-0981(00)00178-7 PMid:10969162

Gray, J.S. and T.H. Pearson. – 1982. Objective selection of sensitive species indicative of pollution-induced disturbance change in benthic communities. I: Comparative Methodology. Mar. Ecol. Prog. Ser., 9: 111-119. doi:10.3354/meps009111

Hyland, J., L. Balthis, I. Karakassi, P. Magni, A. Petrov, J. Shine,O. Vestergaard and R. Warwick. – 2005. Organic carbon content of sediments as an indicator of stress in the marine benthos. Mar. Ecol. Prog. Ser., 295: 91-103. doi:10.3354/meps295091

Karakassis, I. and A. Eleftheriou. – 1997. The continental shelf of Crete: structure of macrobenthic communities. Mar. Ecol. Prog. Ser., 160: 185-196. doi:10.3354/meps160185

Koulouri, P., D. Koutsoubas and C. Dounas. – 2000. Structure and dynamics of the infralittoral molluscan assemblages (soft substrate) in Heraklion Bay (Crete, Eastern Mediterranean). Proc. 6th Hellenic Symp. Oceanogr. Fish. (Chios), pp. 355-360. Greece.

Koutsoubas, D. – 1992. Contribution to the study of the gastropod molluscs of the continental shelf of the North Aegean Sea. Ph. D. thesis, Aristotle Univ. Thessaloniki, Greece.

Koutsoubas, D., A. Koukouras, I. Karakassis and C. Dounas. – 1992. Contribution to the knowledge of Gastropoda and Bivalvia (Mollusca) of Crete Island (S. Aegean Sea). B. Malacol., 28(1-4): 69-82.

Newell, R.C., L.J. Seiderer and J.E. Robinson. – 2001. Animal: sediment relationships in coastal deposits of the eastern English Channel. J. Mar. Biol. Assoc. U.K., 81: 1-9. doi:10.1017/S0025315401003344

Noss, R.F. – 1983. A regional landscape approach to maintain diversity. BioScience, 33: 700-706. doi:10.2307/1309350

Olsgard, F., P.J. Somerfield, and M.R. Carr. – 1997. Relationships between taxonomic resolution and data transformations in analyses of a macrobenthic community along an established pollution gradient. Mar. Ecol. Prog. Ser., 149: 173-181. doi:10.3354/meps149173

Pearson, T.H. and R. Rosenberg. – 1978. Macrobenthic succession in relation to organic enrichment and pollution of the marine environment. Oceanogr. Mar. Biol., 16: 229-311.

Pérès, J.M. – 1967. The Mediterranean benthos. Oceanogr. Mar. Biol., 5: 449-533.

Pérès, J.M. – 1982. Major benthic assemblages. In: O. Kinne (ed.), Marine Ecology, pp. 373-522. J. Wiley & Sons, Chichester.

Psarra, S., A. Tselepides, and L. Ignatiades. – 2000. Primary productivity in the oligotrophic Cretan Sea (NE Mediterranean): seasonal and interannual variability. Prog. Oceanogr., 46: 187-204. doi:10.1016/S0079-6611(00)00018-5

Ricciardi, A. and E. Bourget. – 1998. Weight-to-weight conversion factors for marine benthic macroinvertebrates. Mar. Ecol. Prog. Ser., 163: 245-251. doi:10.3354/meps163245

Rueda, J.L., Fernández-Casado, M. Salas, C. and Gofas, S. 2001. Seasonality in a taxocoenosis of molluscs from soft bottoms in the Bay of Cádiz (southern Spain). J. Mar. Biol. Assoc. U.K., 81: 903-912.

Samuelson, G.M. – 2001. Polychaetes as indicators of environmental disturbance on subarctic tidal flats, Iqaluit, Baffin Island, Nunavut Territory. Mar. Pollut. Bull., 42(9):733-41. doi:10.1016/S0025-326X(00)00208-3 PMid:11585065

Sabelli, B., R. Gianuzzi-Savelli and D. Bedulli. – 1990. Catalogo annotato dei Molluschi Marini del Mediterraneo. Libreria Naturalistica Bolognese, Bologna.

Smith, W. and A.D. McIntyre. – 1954. A spring-loaded bottom sampler. J. Mar. Biol. Assoc. U.K., 33: 257-264.

Thompson, B.W., M.J. Riddle, J.S. Stark. – 2003. Cost-efficient methods for marine pollution monitoring at Casey Station, East Antarctica: the choice of sieve mesh-size and taxonomic resolution. Mar. Pollut. Bull., 46: 232-243. doi:10.1016/S0025-326X(02)00366-1 PMid:12586119

Todd, J.A. – 2005. Introduction to molluscan life habits databases. Neogene Marine Biota of Tropical America.

Tselepides, A., K.-N. Papadopoulou, D. Podaras, W. Plaiti and D. Koutsoubas. – 2000. Macrobenthic community structure over the continental margin of Crete (South Aegean Sea, NE Mediterranean). Prog. Oceanogr., 46: 401-428. doi:10.1016/S0079-6611(00)00027-6

UNEP (United Nations Environmental Programme). – 1992. Convention on Biological Diversity-text and annexes. Secretariat for the Convention on Biological Diversity, Chatelaine, Switzerland.

Warwick, R.M. and K.R. Clarke. – 1994. Relearning the ABC: taxonomic changes and abundance/biomass relationships in disturbed benthic communities. Mar. Biol., 118: 739-744. doi:10.1007/BF00347523

Warwick, R.M. and K.R. Clarke. – 2001. Practical measures of marine biodiversity based on relatedness of species. Oceanogr. Mar. Biol. Ann. Rev., 39: 207-231.

Warwick, R.M., N.R. Collins, J.M. Gee and C.L George. 1986. Species size distributions of benthic and pelagic Metazoa: evidence for interaction. Mar. Ecol. Prog. Ser., 34: 63-68. doi:10.3354/meps034063

Warwick, R.M., H.M. Platt, K.R. Clarke, J. Agard and J. Gobin. – 1990. Analysis of macrobenthic and meiobenthic community structure in relation to pollution and disturbance in Hamilton Harbour, Bermuda. J. Exp. Mar. Biol. Ecol., 138: 119-142. doi:10.1016/0022-0981(90)90180-K

Zenetos, A. – 1996. Classification and interpretation of the established Mediterranean biocoenoses based solely on Bivalve Molluscs. J. Mar. Biol. Assoc. U.K., 76: 403-416.

Copyright (c) 2006 Consejo Superior de Investigaciones Científicas (CSIC)

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Contact us

Technical support