Soil and Sediment Contamination, 21:673–700, 2012 Copyright © Taylor & Francis Group, LLC ISSN: 1532-0383 print / 1549-7887 online DOI: 10.1080/15320383.2012.691128 Assessment of Trace Metals Contamination in the Suspended Matter and Sediments of a Semi-enclosed Mediterranean Gulf GEORGIOS SYLAIOS, 1 NIKOLAOS KAMIDIS, 1,2 AND NIKOLAOS STAMATIS 2 1 Laboratory of Ecological Engineering & Technology, Department of Environmental Engineering, Democritus University of Thrace, Xanthi, Greece 2 National Agricultural Research Foundation, Fisheries Research Institute, Kavala, Greece This study investigates the distribution of heavy metals in the suspended particulate matter and the sediments of Kavala Gulf, located in Northern Greece. Particulate trace metals were determined in accordance to water column physicochemical parameters. Metals in sediments were related to the textural characteristics, the organic matter, and carbonate contents of surficial sediments. Results illustrated that the diverse human coastal activities influence the distribution of particulate and sediment metal concen- trations, since lower trace metal levels were detected along the western (tourism) and eastern (aquaculture) coast, while increased values were observed at the central (urban and industrial). Overall, particulate metals show moderately low levels compared to other similar sites, with the exception of Ni and Cd depicting local peaks along the industrial coastal zone. Significantly increased levels for particulate lead (123.1 μg/g) and chromium (113.9 μg/g) were detected at the sites near the industrial zone. Direct effluents from a fertilizer plant appeared responsible for the increased Pb, Cr, and Cd levels, while the increased values in Zn, Cu, and Hg appear related to phosphogypsum leaching. Sediment contamination assessment indicated that the Kavala Gulf is char- acterized by clean to marginally polluted sediments, with moderately severe pollution levels along the urban coastline. Keywords Heavy metals, suspended particulate matter, sediment, enrichment factor, pollution index, Kavala Gulf 1. Introduction Heavy metals such as arsenic (As), cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), and zinc (Zn) pose a serious risk to the health of aquatic ecosystems due to their short- and long-term toxicity (Foerstner and Wittmann, 1983). Industrial and agricultural activities, as well as urban effluents, are the major anthropogenic sources, supplying important loads of these metals to the coastal environment. As coastal areas are world-productive marine ecosystems, serving as feeding, nursery grounds, and Address correspondence to Georgios Sylaios, Laboratory of Ecological Engineering & Technology, Department of Environmental Engineering, Democritus University of Thrace 67100, Xanthi, Greece. E-mail: gsylaios@env.duth.gr 673