ISSN 1067-4136, Russian Journal of Ecology, 2006, Vol. 37, No. 1, pp. 60–65. © Pleiades Publishing, Inc., 2006.
Original Russian Text © I.N. Zalicheva, V.S. Ganina, N.K. Shustova, 2006, published in Ekologiya, 2006, Vol. 37, No. 1, pp. 64–69.
The anthropogenic acidiﬁcation of surface waters in
northwestern Russia is an increasingly acute problem.
Studies on the ecological consequences of acidiﬁcation
are mainly performed by traditional hydrobiological
methods, which can reveal the structure of a biocenoses
but provide almost no information on its functional
state. Therefore, it is necessary to develop methodology
and techniques for the long-term monitoring of water
acidiﬁcation in large geographic areas and for the eco-
logical rating of pH values for water bodies of different
types according to their zonal and regional features.
Natural differences in the chemical composition of
continental waters obviously have an effect on biologi-
cal processes in water bodies. Our long-term studies on
the tolerance of freshwater ecosystems to toxic load
have shown that this parameter has distinct zonal fea-
tures and, hence, the anthropogenic transformation of
aquatic biocenoses occurs in markedly different ways,
depending on concrete natural conditions, even when
the factors responsible for it are the same (Volkov
1993, 1996, 1998, 2000; Zalicheva and Volkov, 1994).
Water bodies of the taiga zone differ from most
water bodies located in other natural zones: on average,
30% of their drainage area is boggy, and this accounts
for a high content of humic substances and hydrogen
ions responsible for water acidity. Water pH in almost
70% of lakes in the taiga zone is below 7.0, whereas
67% of lakes in the zone of mixed forests have a pH
higher than 8.0 (Kitaev, 1984).
The biological consequences of acidiﬁcation
depend on geographic factors (location, landscape, and
characteristics of drainage area), as well as on hydro-
logic, hydrochemical, and morphological parameters of
a water body. However, the structure and functional
state of aquatic biocenoses in acid water bodies is ulti-
mately determined by the ecological valence of hydro-
bionts at different trophic levels and by their evolution-
arily established norm of reaction to speciﬁc conditions
of the acidiﬁcation of the aquatic environment.
Some authors (Vinogradov, 1979; Alabaster and
Lloyd, 1984; Schom, 1986; Lebedeva, 1990) note that
ﬁsh and other hydrobionts are capable of adaptation
(acclimation) to water pH gradually decreasing to lethal
values, with typical freshwater forms undergoing this
adaptation more easily than euryhaline and marine
forms. Some salmons, including
, differ in
their tolerance to low pH. Studies performed by Robin-
(1976) on inbred strains of brook trout
revealed the possibility of a hereditary tolerance to acid-
ity even in ﬁshes from normal (not acid) water bodies.
Thus, in polluted acid waters, selection for strains with
hereditary tolerance to acidiﬁcation may take place.
Unfortunately, although numerous hydrochemical
and hydrobiological studies have been performed by
Russian and foreign scientists in different regions,
including the taiga zone, there are still almost no data
on the biotic component accounting for the tolerance of
aquatic cenoses to water acidity. The purpose of our
studies was to analyze interspeciﬁc, interpopulation,
and age-dependent features of the tolerance to acidiﬁ-
cation in representative and indicator species from
Karelian freshwater ecosystems of the taiga natural cli-
Ecotoxicological Aspects of the Tolerance of Hydrobionts
to Acidification of the Aquatic Environment
in the Taiga Natural Climatic Zone
I. N. Zalicheva, V. S. Ganina, and N. K. Shustova
Northern Research Institute of Fisheries, Petrozavodsk State University,
nab. Varkausa 3, Petrozavodsk, Karelia, 185031 Russia
Received March 3, 2004
—Experimental ecotoxicological studies on the norm of reaction to anthropogenic acidiﬁcation were
performed with representative hydrobionts from aquatic ecosystems of the northern taiga zone. Interspeciﬁc,
interpopulation, and age-related differences in tolerance to acidity and the signiﬁcant dependence of this param-
eter on water pH in natural habitats of corresponding populations were revealed.
: aquatic ecosystems, anthropogenic acidiﬁcation, population reaction norm.