Bathymetric and benthic characterisation of Çardak Lagoon, Turkish Straits System

Rıdvan Kaan Gürses, İsmail Burak Daban, Yusuf Şen

ORCID IDs: R.K.G.: 0000-0001-5951-2308; İ.B.D.: 0000-0002-2973-5698; Y.Ş.: 0000-0002-0595-4618

Turkish Marine Research Foundation (TUDAV), P.O. Box: 10, Beykoz, Istanbul, TÜRKİYE
Department of Fisheries and Fish Processing, Faculty of Marine Science and Technology, Çanakkale Onsekiz Mart University, Çanakkale, TÜRKİYE
Department of Marine Biology, Faculty of Marine Science and Technology, Çanakkale Onsekiz Mart University, Çanakkale, TÜRKİYE

Abstract

This study presents the first integrated bathymetric and benthic habitat characterisation of Çardak Lagoon, a coastal lagoon adjacent to the Çanakkale Strait. High-resolution mapping was performed via systematic field surveys across 45 stations, distributed on a 200 × 200 m regular GIS grid. Bathymetric data were obtained through dual-method verification (handheld echo sounder and manual sounding), while benthic substrates were characterised at each station using in situ scientific diving. Bathymetric surfaces were reconstructed using Triangulated Irregular Network interpolation, and benthic habitats were spatially delineated via Voronoi tessellation. The lagoon encompasses a surface area of 1.39 km² with a total water volume of 1.22 × 10⁶ m³ and a volumetrically weighted mean depth of 0.88 m (maximum depth: 3.10 m). The system is dominated by six benthic habitat types: sand–gravel, fine sand, algae–gravel, mixed Zostera–shell substrates, mud/silt, and silt–clay. Coarser-grained sediments are predominantly confined to the high-energy inlet zone, whereas finer-grained facies accumulate within the central and inner basins, reflecting distinct hydrodynamic energy gradients. Due to its pronounced shallowness and restricted marine connectivity (single 57.5 m wide outlet), the lagoon is exceptionally sensitive to atmospheric forcing, and thermal fluctuations. This physical baseline provides a robust framework for hydrodynamic modelling, sediment budget analyses, and long-term monitoring programs essential for detecting early warning signals of ecological regime shifts under projected climate change and anthropogenic pressures. These high-resolution datasets serve as critical inputs for adaptive management strategies aimed at preserving this first-degree natural protected area within one of the world’s most intensively utilised maritime corridors.

Keywords: Coastal lagoon, bathymetry, benthic habitat mapping, GIS modelling, Çanakkale Strait, Turkish Straits System

Pages: 32-43

References

Acar, S., Ateş, A.A. (2021) Feeding ecology of portunid crab, Carcinus aestuarii Nardo, 1847 in Çardak Lagoon (The Turkish Straits System). Ege Journal of Fisheries & Aquatic Sciences 38(2): 155-159.

Anthony, A., Atwood, J., August, P., Byron, C., Cobb, S., Foster, C., Fry, C., Gold, A., Hagos, A., Heffner, L., Kellogg, D.Q., Lellis-Dibble, K., Opaluch, J.J., Oviatt, C., Pfeiffer-Herbert, A., Rohr, N., Smith, L., Smyth, T., Swift, J., Vinhateiro, N. (2009) Coastal lagoons and climate change: ecological and social ramifications in US Atlantic and Gulf coast ecosystems. Ecology and Society 14(1): 8.

Ateş, A.S., Büyükateş, Y., Acar, S. (2025) Temporal and spatial status of environmental variables and pollutants in Çardak Lagoon (Çanakkale Strait). Aquatic Research 8(3): 186-206.

Ateş, A.S., Mülayim, A., Bakir, A.K., Acar, S., Büyükateş, Y., Dağlı, E., Doğan, A., Uzundumlu, S., Kedioğlu, Ç. (2023) Temporal and spatial effects of environmental variables on crustacean communities in Çardak Lagoon (Turkish Straits System) under the influence of domestic pollution. Biologia 78(9): 2371-2384.

Burrough, P.A., McDonnell, R.A., Lloyd, C.D. (2015) Principles of Geographical Information Systems. Oxford University Press, Oxford, UK.

Can, E., Kevrekidis, T., Cihangir, B. (2009) Factors affecting monthly variation in population density of the capitellid polychaete Heteromastus filiformis in a hyperhaline Mediterranean coastal lagoon. Transitional Waters Bulletin 3(3): 10-23.

Dağlı, E., Ateş, A.S., Acar, S., Büyükateş, Y., Doğan, A., Bakır, A.K. (2023) Exotic polychaetes of a sewage pollution influenced lagoon (Çardak Lagoon, Turkish Straits). Sustainability 15(11): 8946.

Duarte, C.M., Losada, I.J., Hendriks, I.E., Mazarrasa, I., Marbà, N. (2013) The role of coastal plant communities for climate change mitigation and adaptation. Nature Climate Change 3(11): 961-968.

Fortune, S. (1987) A sweepline algorithm for Voronoi diagrams. Algorithmica 2: 153-174.

Franco, A., Franzoi, P., Malavasi, S., Riccato, F., Torricelli, P., Mainardi, D. (2006) Use of shallow water habitats by fish assemblages in a Mediterranean coastal lagoon. Estuarine, Coastal and Shelf Science 66(1-2): 67-83.

Kjerfve, B. (1994) Coastal Lagoons. In: Coastal Lagoon Processes (ed., Kjerfve, B.), Elsevier Oceanography Series Vol. 60, Elsevier, Amsterdam, pp. 1-8.

Kjerfve, B., Magill, K.E. (1989) Geographic and hydrodynamic characteristics of shallow coastal lagoons. Marine Geology 88(3-4): 187-199.

Lenzi, M., Cianchi, F. (2022) Summer dystrophic criticalities of non-tidal lagoons: the case study of a Mediterranean lagoon. Diversity 14(9): 771.

Molinaroli, E., Sarretta, A., Ferrarin, C., Masiero, E., Specchiulli, A., Guerzoni, S. (2014) Sediment grain size and hydrodynamics in Mediterranean coastal lagoons: Integrated classification of abiotic parameters. Journal of Earth System Science 123(5): 1097-1114.

Okabe, A., Boots, B., Sugihara, K., Chiu, S.N., Kendall, D.G. (2000) Spatial Tessellations: Concepts and Applications of Voronoi Diagrams. 2nd Edition, John Wiley & Sons, Chichester, UK.

Öztürk, B., Öztürk, A.A. (1996) On the biology of the Turkish straits system. Bulletin de l’Institut Océanographique Monaco No. Spécial 17: 205-221.

Peucker, T.K., Fowler, R.J., Little, J.J., Mark, D.M. (1978) The Triangulated Irregular Network. In: Digital Terrain Models Symposium, American Society of Photogrammetry, St. Louis, Missouri, pp. 516-540.

Polidori, L., El Hage, M. (2020) Digital elevation model quality assessment methods: A critical review. Remote Sensing 12(21): 3522.

Ralph, P.J., Durako, M.J., Enriquez, S., Collier, C.J., Doblin, M. A. (2007) Impact of light limitation on seagrasses. Journal of Experimental Marine Biology and Ecology 350(1-2): 176-193.

Soria, J., Pérez, R., Sòria-Pepinyà, X. (2022) Mediterranean coastal lagoons review: Sites to visit before disappearance. Journal of Marine Science and Engineering 10(3): 347.

Tagliapietra, D., Sigovini, M., Ghirardini, A.V. (2009) A review of terms and definitions to categorise estuaries, lagoons and associated environments. Marine and Freshwater Research 60: 497-509.

Thiessen, A.H. (1911) Precipitation averages for large areas. Monthly Weather Review 39(7): 1082-1089.