The chemical oceanographic consequences of environmental restoration projects in the Golden Horn estuary (Marmara Sea, Turkey)

Abstract

The input of industrial and domestic waste to the horizontal circulation in the Golden Horn Estuary of Marmara Sea has resulted in one of the most polluted estuaries in the past. Consequently, the dissolved oxygen concentrations in both the surface and bottom waters decreased toward to the estuary head during 1998-2005. In contrast, the total suspended solids content of the surface water decreased toward to the estuary mouth. However, construction of the operational collector system surrounding the estuary during the process of rehabilitation projects, combined with the opening of the middle pontoons of the Valide Sultan Bridge, resulted in gradually improved water quality of the estuary with a concomitant decrease in pollution. However, phytoplankton blooms and eutrophication persist especially in the innermost part of the Golden Horn in 2005. The region from the estuary mouth up to Camialti has a dynamic structure, and sufficient circulation seemingly occurs in this part of the Golden Horn.

Effect of Seasonal Changes on Steroid Hormones Concentrations in the Golden Horn Estuary (Sea of Marmara, Turkey)

“…In this study, the highest value of total suspended solid (24.6 mg/L) was determined in bottom water at the Sünnet Bridge, in winter season. Similarly, Balkis et al (2010) reported the highest total suspended solids in the bottom water at Sünnet Bridge station. The high level of total suspended solids indicated that the intense organic, terrestrial and human-induced burdens (micropollutants; hormones) originating from streams and precipitation accumulates in the inner region of the Golden Horn.…”

“…4 and 5). Balkis et al (2010) reported that the total suspended solids values are higher especially in the inner part of the Golden Horn (ES-SB). Streams, precipitation and terrestrial inputs through the biological activities are responsible for controlling the distribution in the inner regions.…”

Relative contribution of the presence of an estuarine dam and land reclamation to sediment dynamics of the Nakdong Estuary

“…Second, this study can provide considerable knowledge about the sedimentary responses for the restoration of an estuary where multiple human alterations already occurred. Although numerous studies have been conducted for the restoration of altered estuaries, many of them were focused on the improvement of fisheries (Bergstrom et al, 2004;Blomberg et al, 2018) and water quality problems (Smit et al, 1997;Balkis et al, 2010). On the other hand, studies on sedimentary changes for the restoration of an estuary were rare (George et al, 2012) because sedimentary and morphological responses take a relatively long period of time compared to chemical and biological responses.…”