Petryashov et al.: Macrobenthos Distribution in the Laptev Sea
173
waters with salinities of 15 to 30); (4) Leionucula bellotii; and (5) Tridonta borealis (further
north-westward) . In the northern Laptev Sea, macrobenthic assemblages characterized by the
following species were found in different depth zones: by the brittle stars (6)Ophiocten
sericeum; (7) 0. sericeum, associated with Ophiacantha bidentata and Ophiopleura borealis;
(8) by polychaetes of the family Maldanidae, associated with the polychaete Spiochaetopterus;
and (9) by the holothurian Kolga hyalina, associated with the sea urchin Pourtalesia jeffreysi
and the sea cucumber Elpidia sp.
50 m
92 m
186 m
en
232 m
c
0
Biogeographic Composition
o Arctic
g Boreal Arctic
~
Atlantic Boreal Arctic
Pacific Boreal Arctic
Widespread
64
42
30
39
Z
c
3
0ro .....
0
-
(fJ
292 m
-.;::
ctl
2 1 -a
- en 520 m
- 0
en
540 m
.r:.
- 0- 889 m
Q)
-a
'Q)
-- ctl
$
o
20
40
60
80
Species Percentages (%)
30
39
28
24
20
8
1 0
1 0
100
Figure 3: Species percentages of different biogeographic groups at stations in depths ranging from 50 to 3080 m.
Trophic structure
Two major trophic zones were distinguished (Figure 5): one dominated by deposit feeders, and
the other dominated by suspension feeders. The first covers the larger part of the Laptev Sea,
encompassing nearly all regions in which a transformation of riverine waters occurs: the bottom
depression of the Sadko Trough, the continental slope, as well as probably most of the outer
ro
(')
ai'
(fJ
.....
ro
(')
0 .....
0ro
0III
- en
- III
- 0'
~
(fJ