Physical Oceanography, Vol.
4, November, 2011 (Ukrainian Original No.
4, July–August, 2011)
EXPERIMENTAL AND FIELD RESEARCH
REGULARITIES OF SEASONAL VARIATIONS IN THE CONTENT AND
DISTRIBUTION OF OXYGEN IN WATERS OF THE SEVASTOPOL BAY
S. V. Svishchev,
S. I. Kondrat’ev,
and S. K. Konovalov
We study the regularities of annual variations in the concentration of oxygen and the degree of saturation
of waters in the Sevastopol Bay with oxygen in 1998–2009. The three-dimensional specific features of
seasonal variations in the distribution of oxygen in waters of the Sevastopol Bay are revealed. Two pe-
riods can be separated in the annual course of the content of oxygen in the surface layers of waters in all
parts of the bay: the period of supersaturation in March–September and the period of undersaturation in
October–February. In the bottom layer of waters in all parts of the bay, we observe the undersaturation
of waters with oxygen for the whole year.
Keywords: concentration of oxygen, degree of saturation with oxygen, Sevastopol Bay.
The extensively exploited coastal marine systems, including the Sevastopol Bay, undergo the action of ele-
vated anthropogenic loads, including the factors of extremely extensive utilization of natural resources, introduc-
tion of alien species, contamination of the environment (ejections of household and industrial waste waters, etc.)
. As one of the fundamental indicators of undesirable changes in the state of marine ecosystems, one can
mention the variations of the oxygen conditions.
The dissolved oxygen and the degree of saturation of waters with oxygen characterize the state of the ma-
rine ecosystem, the comfort of existence of biological communities, the intensity of running of the main biologi-
cal and biochemical processes, and the stability of the hydrochemical conditions. For this reason, the data on the
oxygen conditions in the coastal water areas of the sea in general and in the Sevastopol Bay in particular is of
primary importance for the purposes of planning of their rational utilization in various branches of the economic
activity of the society.
As one of the most typical negative changes in the state of marine media, one can mention the deficiency of
oxygen (hypoxia) and, in the liming case, the absence of oxygen (anoxia). Note that the term “anoxia” has the
unambiguous definition and corresponds to the analytical absence of oxygen, i.e., usually to concentrations
lower than 0.02 ml/liter. At the same time, the term “hypoxia” is ambiguous. This is explained by the fact that
this term was initially specified as the level of oxygen content corresponding to the appearance of negative
physiological reactions in biological communities. Since different biological communities are characterized by
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol, Ukraine.
Corresponding author; e-mail: email@example.com.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
64–78, July–August, 2011. Original article submitted January 21, 2010;
revision submitted July 12, 2010.
280 0928–5105/11/2104–0280 © 2011 Springer Science+Business Media, Inc.