1063-0740/02/2805- $27.00 © 2002
Russian Journal of Marine Biology, Vol. 28, No. 5, 2002, pp. 293–297.
Original Russian Text Copyright © 2002 by Biologiya Morya, Murakhveri, Shepel’, Arzamastsev, Vyushkvartsev.
In the past, the Tumannaya River entered Eks-
peditsii Bay, which is also currently still directly
affected sometimes by the waters of this large river via
the ancient riverbed (now the Karasik River) after
typhoons or heavy rainfalls. These ﬂoods may cause
catastrophic desalination of waters in the bay .
The benthos communities of shallow water bays in
Pos’eta Bay, including Ekspeditsii Bay, are affected by
water and pollution entering it from the marine mouth
area of the Tumannaya River  due to the tides [15,
21], positive and negative wind patterns, and the arising
compensatory currents (N.I. Grigor’eva, pers. comm.).
Some scientists who have studied bottom communi-
ties in Ekspeditsii Bay mentioned the silting of the bay
starting in the 1930s. Most publications, however, deal
with studies of certain benthos communities on upper
subtidal horizons [7–9, 11, 12, 16], oyster beds that
ﬂourished previously , and the inner geomorphol-
In most bottom areas of the bay occupied by soft
silts, the biota is not well studied, except for the very
rich biota of biogerms .
The target of this project was to estimate the compo-
sition of dominating organisms and their population
density and biomass on the accumulative plains and
slopes of Ekspeditsii Bay. This study was a part of a
large framework project of studies on the ﬁeld of ther-
apeutic muds located in the bay.
MATERIALS AND METHODS
The materials were collected in July–September
1996 at 128 scuba stations (see ﬁgure) distributed
throughout Ekspeditsii Bay from 0.5 m deep and
greater. The location of the stations was determined
using a compact GPS satellite navigation system.
The macrobenthos was sampled using a scuba sedi-
ment corer and a frame. The epifauna was collected
from an area of 1–10 m
, and the macrophytes and
infauna were sampled from areas of 0.25 and 1 m
respectively. Altogether, 277 qualitative samples were
collected at the stations. After removing the seawater,
the collected hydrobionts were weighted with an EK-
1200A balance (accurate to 0.1 g). During the treat-
ment of the collected materials, stations with similar
ground patterns were united into particular bottom
regions, whose areas were estimated with a map using
the Berlyant method . The total area of Ekspeditsii
Bay is 80.9 km
. The density and biomass of the
dominant benthic organisms were calculated as mean
values for all stations in the speciﬁed areas.
Macrobenthos of Accumulative Plains and Slopes of Ekspeditsii
Bay (Pos’eta Bay, Sea of Japan)
A. M. Murakhveri
, N. A. Shepel’
, I. S. Arzamastsev
, and D. I. Vyushkvartsev
Paciﬁc Institute of Geography, Far East Division, Russian Academy of Sciences, Vladivostok, 690041 Russia
Paciﬁc Center of Scientiﬁc Fisheries, Vladivostok, 690001 Russia
Joint-Stock Company “Primorrybprom”, Vladivostok, 690090 Russia
Institute of Marine Biology, Far East Division, Russian Academy of Sciences, Vladivostok, 690041 Russia
Received November 20, 2001
—The submarine accumulative plain of Ekspeditsii Bay is heterogeneous in terms of ground pattern
and the composition and biomass of macrobenthos. The smallest values of the total biomass are characteristic
of soft pelites (58.9 g/m
), siltstone pelites (55.9 g/m
), and pelites with an insigniﬁcant admixture of broken
mollusk shells (108 g/m
). The greatest total biomass (649.2 g/m
) is registered around biogerms, in bottom
areas composed of pelites with large fragments and entire valves of mollusk shells. On accumulative slopes of
the bay, in the community of seagrasses,
constitutes 90% of the biomass and macrofauna pro-
vides the remaining 10%. The values of the total biomass of macrobenthos of the accumulative plain and mac-
roﬂora of the accumulative slopes of the bay are close to each other (about 12000 tons); however, both values
are only 0.4 times as great as the biomass of macrobenthos on biogerms that occupy only 6.2% of the total bot-
tom area in the bay.
benthos, biomass, siltstone pelites, shallows, Sea of Japan.