Physical Oceanography, Vol.
EXPERIMENTAL AND FIELD RESEARCH
POLAROGRAPHY OF THE BOTTOM SEDIMENTS IN THE SEVASTOPOL BAY
N. A. Orekhova and S. K. Konovalov
UDC 551.465 (262.5)
By the method of polarographic profiling performed with the help of an Au-Hg glass microelec-
trode, we obtained the first high-resolution vertical profiles of the distributions of oxygen, sul-
fides, oxidized and reduced forms of iron, reduced manganese, and iron monosulfide in pore wa-
ters of the bottom sediments in the Sevastopol Bay. It is shown that the regional features of the
vertical distributions of the main polarographically active compounds are determined by the
combination of several factors: the contents of organic carbon and iron and the sizes of particles
of the sediments.
The Sevastopol Bay is one of marine water areas subjected to strong permanent anthropogenic influence.
On the one hand, the bay plays the role of a city-forming element of the geosphere. On the other hand, for a long
period of time, it serves as a naval base with all typical industrial and economic infrastructures. The intense
many-year investigations of the consequences of influence of the city and navy upon the ecosystem of the bay
 are directed toward the analysis of the hydrological, hydrochemical, and biological characteristics of waters
and the mean characteristics of the upper layer of bottom sediments . In the present work, we consider the
possibility of application of the method of polarographic profiling to the investigation of the processes running in
The Sevastopol Bay is an estuary-type water area of about
in length with a mean width of
Its mean depth is equal to
and the maximum depth to
. The Sevastopol Bay is characterized by
high rates of accumulation of sediments:
. The municipal sewage of the city plays the role of a
source of large amounts of biogenic elements coming into the bay. The ecosystem of the Sevastopol Bay
reached the eutrophic level, whereas some parts of the bay (e.g., the Yuzhnaya Bay) are characterized by the hy-
pertrophic stage accompanied by the development of hypoxia in the bottom layers of water and the accumulation
of organic carbon in the bottom sediments. The discharge of industrial wastes into the water area of the bay re-
sults in the accumulation of various metals in the sediments . Under certain conditions, these sediments may
turn into a source of secondary pollution of the entire water column. The variations in the physicochemical con-
ditions (especially in the pH values and Eh), e.g., the oxidation of anaerobic sediments due to their periodic roil-
ing (the Sevastopol Bay is a zone of intense navigation), may lead to changes in the degree of oxidation of the
metals accumulated in the sediments. This, in turn, is accompanied by the changes in the migration ability of the
metals, which become better accessible for the microorganisms [4, 5]. The exhaustion of the supply of oxygen
in marine systems due to the restriction of its flow or as a result of the increase in the rate of its consumption
leads to the formation of hydrogen sulfide and its interaction with metals.
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol, Ukraine.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
52–66, March–April, 2009.
Original article submitted November 7,
2007; revision submitted November 25, 2007.
0928-5105/09/1902–0111 © 2009 Springer Science+Business Media, Inc. 111