Physical Oceanography, Vol. 15, No. 1, 2005
EXPERIMENTAL AND FIELD RESEARCH
INFLUENCE OF ATMOSPHERIC PROCESSES ON THE LONG-PERIOD
VARIATIONS OF THE BIOMASS OF ANCHOVY
V. S. Latun
UDC 639.2.053.1:639.222.6 (262.5)
We study the influence of large-scale atmospheric processes on the cyclic variations of the bio-
mass of anchovy in the Black Sea and analyze the mechanism of action of various ecological
factors on its productivity. A conclusion is made that the 4–6-yr periodicity of variations of the
biomass of anchovy is caused by the cyclicity of the weather conditions and environmental pro-
cesses in the Black-Sea basin connected with the North-Atlantic oscillation.
At present, anchovy is the main commercial fish in the Black Sea. At the end of the previous century, the
annual catch of anchovy exceeded
i.e., more than
of the total catch of fish in the Black Sea
. Therefore, the problem of control over fishery reduces, for the most part, to the catch of anchovy. As the
main components of the required control, we can mention the necessity of prediction of the variability of the bio-
mass of anchovy and substantiation of its maximum permissible catch.
In predicting the biomass of anchovy and its commercial resources, it is necessary to take into account the
trends of changes in the structure of biocenosis and the characteristics of the habitat, as well as the basic periodic
annual and many-yea variations. The annual cycle of anchovy is well studied [2, 3]. In the many-year variabil-
ity of catch and resources of the main species of commercial fish in the Black Sea, the authors of  approxima-
The following reasoning leads to the conclusion that a certain periodicity can be observed in the interannual
variations of the biomass of anchovy. In the spawning population of anchovy of a productive year, two- and
three-year-old fish are predominant but the fractions of groups of different age may vary from year to year within
fairly broad limits [5, 6]. If the biomass of anchovy is large but the environmental conditions of a specific year
are unfavorable for spawning, then this year’s brood is relatively small and, hence, the population of spawning
anchovy will change after
yr. However, if the conditions of spawning in
would be favorable, then,
after a new period of
the number of spawning fish of the most productive age and its commercial re-
sources would again increase.
If the variations of the biomass of anchovy are indeed characterized by the presence of
then its main cause should be connected with the variability of the conditions of spawning, i.e., with similar peri-
odicity of the environmental conditions. It is necessary to answer the following three questions:
1. Is it true that the variations of the biomass of anchovy contain cycles with a period of
2. Are there any ecological disturbances with the same period?
3. What mechanism is responsible for the influence of environmental conditions on the productivity of an-
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
55–62, January–February, 2005. Original article submitted June 4, 2003.
50 0928-5105/05/1501–0050 © 2005 Springer Science+Business Media, Inc.