ISSN 1063-0740, Russian Journal of Marine Biology, 2009, Vol. 35, No. 1, pp. 87–96. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © O.A. Ivanov, 2009, published in Biologiya Morya.
More than 30 research ship voyages aimed at eco-
system survey were conducted by the TINRO-Center
from 1981 to 2003 in the north-western Sea of Japan.
During these voyages, the standard methods were
used to perform pelagic trawlings combined with com-
plex oceanological and planktonological surveys.
Some recently published monographs [1, 9] contain
detailed reports on data collected in these voyages, pre-
sented in cartographic and table forms. The present
work summarizes the same data in terms of zoogeo-
graphical research. In particular, the north-western Sea
of Japan has been subdivided into latitudinal zones on
the basis of species distribution areas of pelagic nekton.
The paper does not include a rather voluminous list of
nekton species with the zoogeographical status of the
species, the list was published earlier .
The water area under study was subdivided into
zones of a uniform zonal-geographical status of nekton
species with the use of a new approach to biogeograph-
ical subdivision . The main principles of this
approach are as follows. Computerized mapping is
based on the concept of continuation approach to zon-
ing: schematic maps present distribution of some quan-
titative biogeographical indicator as a continuous ﬁeld.
It was proposed to use the
Index of Latitudinal Zoning
of species  (Fig. 1) as such a biogeographical indi-
cator. This index is a ﬁgured variant of species areas of
distribution (known by their generally accepted names)
in the system of global latitudinal zones.
Mobility of the pelagial biotope imparts some spe-
cial regularities to geographical distribution of species
The article is translated by the author.
inhabiting the pelagial (and also to distribution of the
communities formed by the species). Inhabitants of the
pelagial contrast with species inhabiting biotopes of
immobile substrates (sea bottom or land). This pecu-
liarity is emphasized by the term “dynamic biogeogra-
phy” , which was introduced by marine biogeogra-
phers and reﬂects the fact that it is not possible to build
common biogeographical schemes either for both land
and sea  or for both sea bottom and the pelagial. One
of the peculiarities of the notion “dynamic biogeogra-
phy” lies in the contradiction between the necessity of
biogeographical subdivision of the pelagial (into
regions, provinces, areas etc.) and continually changing
factors of this speciﬁc environment. In the historical
aspect, climatic zones and landscapes can shift here by
hundreds of miles. Instability of pelagial biotopes in
time and space and their biotopes' boundaries, which
are relatively permeable for nekton species, are the
ground for using the term “dynamic biogeography” at
biogeographical zoning of the pelagial when it is based
on nekton species. No wonder that biogeographical
borders of fragments are in the case some bands with
their own inner structure rather than lines .
Taking into account all the circumstances above, lat-
itudinal zoning of the north-western Sea of Japan based
on distribution areas of the pelagic nekton was con-
ducted in several variants. Besides zoning by combined
data (for methods see ), the zoning was performed
for different time spans. For that, we considered intra-
daily, seasonal and interannual time scales. In accord
with these scales, let us analyze subdivision of the
water area separately for day and night, for different
seasons (spring, summer, autumn, winter) and for dif-
ferent periods of study (1981–1990, 1991–1995, and
Zoogeographic Subdivision of the North-Western Sea of Japan
Based on Species Areas of Pelagic Nekton
O. A. Ivanov
Paciﬁc Fisheries Research Center (TINRO), Vladivostok 690950
Accepted May 16, 2008
—A new approach to biogeographical division was used to divide the north-western Sea of Japan into
fragments with a uniform latitudinal zonal status of pelagic nekton species. This approach is based on comput-
erized plotting of maps representing spatial distribution of continuous ﬁelds. Computer mapping of the study
area was carried out in various time aspects: intradaily, interseasonal, and interannual.
: biogeographical divizion, latitudinal zoning, nekton, epipelagis zone, Sea of Japan.