ISSN 10630740, Russian Journal of Marine Biology, 2012, Vol. 38, No. 4, pp. 299–309. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © V.V. Sukhanov, O.A. Ivanov, 2012, published in Biologiya Morya.
This article discusses the results of zoning the area
of the Sea of Okhotsk, based on data on the species
structures of nekton communities. Using earlier
approaches to the zoning of water bodies (see, for
example, publications on marine ecology and bioge
ography in the 1950s and 1960s), the results had a
noticeable relationship to a researcher’s personal
views. Objective zoning, in which the dependence of
results on a researcher’s subjective opinion is mini
mized, became possible only with the use of suffi
ciently powerful computing means. One of the first
attempts of this kind was described in the work by
Sukhanov et al. .
MATERIAL AND METHODS
The staff of the Applied Biocenology Laboratory at
the Pacific Research Fisheries Center (TINRO Cen
ter) have been studying the waters of the Sea of
Okhotsk according to the standard technique for over
30 years. This sea is distinguished from other Russian
seas by higher fish productivity and its rather large size.
Moreover, almost the entire area of the Sea of Okhotsk
is included in the Russian Economic Zone, which
allows the performance of comprehensive fishery
studies without applying for permission to govern
ments of neighboring countries.
The actual data that we used were the data of
76 research surveys that were organized by the TINRO
Center from 1980 through 2009. A total of 8524 trawl
catches were made during these surveys. It should be
noted that when the data were prepared for computer
processing, the authors faced one rarely mentioned
but serious problem, viz., the great quantity of errors
in the digital data; approximately 10% of the numbers
proved to be incorrect. Most frequently these were
simple misprints, such as incorrect inputting of the
code of a species in the sample, or its abundance or
biomass. Errors of this type were removed by searching
for “surges,” i.e., abnormal values in the table data.
Another source of errors was the list of rare species that
had been recorded in catches once or twice in the
entire 30year period of observations. As a rule, codes
of species like these also appeared to be wrong. The
labor cost for clearing the initial data on the Sea of
Okhotsk was approximately one and a half person
years. We admit that after all the data were processed,
only a 1% error rate remained, although these errors
are not crucial.
Trawl catches were performed 24 hours a day with
midwater trawls, which were equipped with a fine
meshed (10–12 mm) insert that was sewn into the
trawl bag within the last 12–15 m. The individual
organisms that were caught, mainly fish and squid,
were identified to the species level immediately during
sorting of the catch. While preparing the data for com
puter processing, all the species biomasses in catches
were recalculated using catchability coefficients .
The precision of these coefficients is not very high;
however, we believe they should be used when studying
natural communities, but not trawl catches.
In our view, biocenotic zoning means dividing a
studied water body into homogenous areas in a man
ner such that each of them contains a group of com
munities with a similar species structure. As well, fol
BIOLOGY OF COMMUNITIES
Biocenotic Zoning in the Sea of Okhotsk Based on the Species
Structure of Nekton
V. V. Sukhanov
and O. A. Ivanov
Zhirmunsky Institute of Marine Biology, Far East Branch, Russian Academy of Sciences, Vladivostok, 690041 Russia
Far Eastern Federal University, Vladivostok, 690091 Russia
Pacific Research Fisheries Center, Vladivostok, 690091 Russia
Received February 2, 2012
—A computer algorithm is briefly described in this article that allows one to divide the area of a water
body into homogenous zones that contain similar species structures of nekton. The schematic maps show the
results of zoning of the nekton communities using the available data, water layers of various depths, by time
of day, season, and by period of observation.
: biocenotic complex, syntaxon