Records of mitigation measures in the sediments from an urban estuary, Turkey

ALPAR Ş. B., Ünlü S.

ECSA54, Coastal systems under change: tuning assessment and management tools, Sesimbra, Portugal, 11 - 16 May 2014, pp.90

  • Publication Type: Conference Paper / Full Text
  • City: Sesimbra
  • Country: Portugal
  • Page Numbers: pp.90
  • Istanbul University Affiliated: Yes


Heavy metals were monitored in surface sediment from an estuary, the Golden Horn, Istanbul. This urban
estuary has 3 distinct water masses; a very thin freshwater mass, brackish Black Sea water and more saline
Mediterranean water. Rapid urban growth and uncontrolled industrial development (1950-1985), however, led
to tremendous pollution of its water and thick layers of anoxic sediments. Due to ecologically unlivable
conditions it became the main subject of many top priority larger and smaller projects. However, these changes
remained far from initiating a large-scale transformation in the area. At the end of 2012 the municipality started
to transport Black Sea’s clean but more saline (17 psu) water to the Golden Horn through a 14 km tunnel. This
makes surface water denser, easily carrying suspended particulates much farther from the tributaries. As
sedimentation is a continuous process, the sediment bed is probably the best medium to store records about
the pollution history. In order to assess the sediment quality and to highlight the anthropogenic contributions to
heavy metal distributions, selected heavy metals in surface sediments were studied in 2012 and 2013. Multiple
chemometric approaches indicated three different regions along the estuary and revealed natural and
anthropogenic sources with moderate levels of Cu, Zn, Pb and Cd. Mitigation measures conducted at the
estuary affect transport processes but not all over the estuary.